Churn Buster was one of the first dedicated dunning tools for Stripe, and for years it was the default recommendation if you wanted something better than Stripe's built-in retries. The product is solid. The pricing is where it gets complicated, and where a lot of SaaS teams start asking if there's a cheaper way.
Churn Buster (and its sibling brand Churnkey, which overlaps heavily in the market) leans on percentage-based or hybrid pricing that scales with your MRR. That model is fine until it isn't. Here's how it works, when it stops making sense, and what flat-fee alternatives look like on the same numbers.
How Churn Buster prices
Churn Buster's public pricing has shifted over the years, but the structure has generally been:
- A monthly base fee tied to your MRR band
- Additional charges or plan tiers that scale with volume
- In some custom plans, a percentage of recovered revenue on top
At the time of writing, Churn Buster quotes plans starting around $99/month for smaller SaaS and climbing into the $500+/month range as your MRR grows. Larger accounts are custom-quoted, and some customers report percentage components in the 5% to 15% range on recovered revenue.
Churnkey, which is essentially the same category with a broader retention suite (cancel flows, payment forms, analytics), prices similarly. You'll see starting plans around $100 to $200/month with custom enterprise pricing above that.
The headline: you're not paying a flat fee. Your bill grows with your success.
When percentage pricing stops being reasonable
The argument for MRR-based or revenue-share pricing is alignment. The vendor makes more when you make more. Fair enough when you're a $10K MRR startup and the tool costs $99/month.
The problem shows up at scale. Run the numbers on a SaaS at $500K MRR.
Industry data puts involuntary churn around 9% of MRR for typical SaaS, so that's roughly $45,000 a month hitting Stripe as failed payments. A well-tuned multi-channel dunning flow recovers 60% to 80%. Call it 70%, which is $31,500 recovered every month.
| Scenario | Monthly cost | Annual cost |
|---|---|---|
| Churn Buster at $500/mo base (MRR-tiered) | $500 | $6,000 |
| Churn Buster with 10% recovery cut | $3,150 | $37,800 |
| Churn Buster with 15% recovery cut | $4,725 | $56,700 |
| Rekko Pro (flat $129) | $129 | $1,548 |
At $500K MRR, the difference between a mid-range Churn Buster plan with a recovery cut and a flat-fee tool like Rekko can easily exceed $50,000 a year. That's a full engineering hire you're handing to a dunning vendor for running email sequences.
Even the base-fee-only version of Churn Buster at that tier costs roughly $4,500 a year more than Rekko Pro, and you're capped on features.
Where Churn Buster earns its price
Fairness matters. Churn Buster isn't bad value for everyone. A few scenarios where it holds up:
You want cancel flows alongside dunning. Churnkey in particular has invested heavily in voluntary churn features. If you need a cancel page, exit survey, and retention offers in addition to failed payment recovery, the bundled price starts looking more reasonable.
You need deep analytics and cohort reporting. Churn Buster's dashboards and segmentation tools are more mature than most competitors. If your retention team lives in those dashboards daily, there's real value.
You're on the smaller end and don't mind the base fee. At $50K MRR, paying $99/month for a known-quantity tool is a defensible decision. The percentage math doesn't hurt as much because the absolute dollars are small.
You're running multiple billing platforms. Churn Buster supports more than just Stripe. If you process payments on Braintree, Recurly, or others, that broader support can justify the pricing.
Where flat fee wins
For everyone else, the flat-fee model is almost always cheaper over a year of normal operation.
Predictable line item. Your finance team can plan around $49 or $129 a month. They can't plan around "10% of whatever we recover, which depends on how much churn we have, which depends on the economy." Flat fee is boring in the way P&Ls should be boring.
Your upside stays yours. If you tune your sequences and your recovery rate jumps from 60% to 80%, the flat-fee vendor charges you the same. The revenue-share vendor sends you a bigger bill. Your optimization work benefits them, not just you.
No surprise at scale. MRR doubles, your Churn Buster bill probably doubles too. Your Rekko bill stays the same (or moves up one tier if you blow past email caps).
Cheaper to run multi-channel. Adding SMS to a dunning flow lifts recovery 30% to 40%. Flat-fee tools like Rekko include SMS as pay-per-use at cost (Twilio pass-through). Percentage tools often don't offer SMS at all, so you're leaving recovery on the table or paying a separate SMS vendor on top.
A real scenario: $300K MRR SaaS
Let's walk through a concrete example. A B2B SaaS doing $300K MRR with standard SaaS card decline rates.
- Monthly failed payments: ~$27,000 (9% of MRR)
- Recovery rate with good dunning: 70%
- Recovered monthly: ~$18,900
With Churn Buster on a hypothetical plan at $399/month base plus 10% of recovered revenue:
- Base: $399
- Recovery cut: $1,890
- Total: $2,289/month, $27,468/year
With Rekko Essential at $49/month flat, adding roughly $80/month in SMS costs for a multi-channel sequence:
- Base: $49
- SMS: $80
- Total: $129/month, $1,548/year
Difference over one year: $25,920. That's the engineering salary comparison again. And the recovery outcome is not meaningfully different between the two tools, because the underlying playbook (real-time webhook, retry cadence, email plus SMS, pre-auth links) is the same.
The "free-trial-to-custom-quote" trap
One pattern worth flagging. Percentage and hybrid pricing tools often don't publish real pricing. You start with a free trial or a low-friction starter plan, build your sequences, connect your Stripe account, get comfortable with the UI. Then at month three or six, you have a "pricing review" call where the rep explains that to unlock the features you're now relying on, you need to move to a custom plan quoted at your MRR.
This is not inherently shady. Custom pricing is a legitimate GTM model. But it means the sticker price you evaluated at signup is not the price you'll pay at scale. The only way to know your true annual cost is to get it in writing before you invest real implementation effort.
Flat-fee tools avoid this entirely. The price on the pricing page is the price you pay. If you grow, you move up a tier, and the next tier is also on the pricing page. Nothing to negotiate, no rep conversations, no surprises at renewal.
Recovery rates are not the differentiator
One argument Churn Buster and similar premium tools use is that their recovery rates justify the premium. The evidence here is thinner than the marketing suggests.
Independent analyses of dunning tools consistently land in the same 60% to 80% recovery range for any well-configured multi-channel flow. The drivers of recovery rate are:
- Whether you catch failures in real-time (webhooks, not polling)
- Whether you retry on smart timing (not naive every-24-hours)
- Whether you use SMS in addition to email
- Whether you send customers to a pre-authenticated update link
- Whether your copy is any good
Every serious dunning tool, including the flat-fee ones, does the first four. The fifth is on you regardless of vendor. The gap between a well-tuned Rekko account and a well-tuned Churn Buster account is usually within a few percentage points, not the 2x multiple the price difference would imply.
If a vendor tells you their recovery rate is dramatically higher than competitors', ask for data. Real cohort-level evidence, not a case study headline. Most of the time the answer is "we're a few points better on certain segments," which is fine but doesn't justify an order-of-magnitude price premium.
What to ask Churn Buster before you sign
If you're still evaluating Churn Buster and want to get a clean answer on pricing, these are the questions to get on the sales call.
- What's the base monthly fee at my MRR band?
- Is there a percentage component on recovered revenue? If so, what percent and how is "recovered" defined?
- Are there usage caps (emails, SMS, retry attempts)?
- What's the overage rate?
- Does the price change if my MRR grows 2x, 3x, 5x over the contract term?
- Is SMS included or separate?
Get those answers in writing before you compare to alternatives.
Rekko's flat-fee alternative
We built Rekko as the flat-fee answer to this exact problem. Public pricing, no revenue share, no surprise at scale.
| Plan | Price | Stripe accounts | Emails included |
|---|---|---|---|
| Starter | $29/mo | 1 | 1,000 |
| Essential | $49/mo | 3 | 5,000 |
| Pro | $129/mo | Unlimited | 20,000 |
SMS is pay-per-use at Twilio cost. You keep 100% of recovered revenue.
For a deeper feature-by-feature comparison, see our Churn Buster alternative page or the full 2026 dunning comparison.
Try Rekko free
- Flat monthly pricing, no percentage of recovered revenue
- Email plus SMS in one tool
- 5-minute Stripe setup
- Keep 100% of what you recover
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