Looks pretty great! The free tier also looks reasonable. The pricing on the other tiers isn't outrageous either if you use it consistently. Unfortunately, I likely find myself in the big gap between the free tier and the Basic plan. I can't justify yet another subscription that I use only a couple of times a year. That said, I would happily pay the $6 on the months that I use the service. Given the churn issues, I'm surprised more SaaS offerings don't work that way.
Thank you for sharing this perspective! Your proposal is potentially a good middle ground, and I will certainly give this some thought.