Pay-per-execution vs subscription — which actually wins for tools you use occasionally?

Hey everyone 👋

I'm building DataPulse Bulk Engine: three bulk tools (AI image upscaler, 500-URL QR batches, PDF→Markdown) behind one prepaid wallet. Top up once with $5 / $10 / $25, spend only on the jobs you actually run, new accounts get $2 of free credit.

My thesis: nobody uses bulk tools every day. You get a spike — "I need 800 photos upscaled THIS weekend" — then nothing for months. A $20/mo subscription for that feels wrong, so I went pay-per-execution instead.

But I keep second-guessing the model:

1. Would you rather pay one predictable monthly fee, even if you only run two jobs?

2. Does a prepaid wallet feel like credits you'll forget to use (airline-miles energy)?

3. What top-up minimum feels real to you — $5 feels trivial, $25 feels like a commitment?

Roast the model honestly. I still have time to change it before launch day.