Pay-as-you-go vs subscription for AI tools: what actually made you pay?

Curious how people here decide. Most AI tools are sold as monthly plans, but a lot of real usage is bursty: one project in March, nothing until June.

Looking at my own purchases this year, the tools I kept paying for were the ones where I could buy a small amount once and come back later without a plan renewing in the background. The ones I cancelled were all subscriptions I used twice.

Two questions:
1. Has a subscription ever stopped you from trying an AI tool you were genuinely interested in?
2. For the tools you pay monthly for, what makes the recurring price feel fair?

For occasional projects, I’d look beyond “subscription or credits” and check three things: when credits expire, whether failed generations cost anything, and what happens to saved work after cancellation. A one-off purchase with a short expiry can have the same drawback as a subscription.

A monthly plan makes more sense when it supports a recurring task and the allowance is predictable. For a first purchase, showing the cost of one usable result—not just the number of credits—would make the decision much easier. How are you handling failed generations in your pricing?