That is a fair point. I don't think the pricing is unreasonable, but it feels limiting. You could try 1000 variations until you find what you need perfectly, but in that pricing model users will be induced to use less the tool, not more.

I'd prefer an option to pay like 200 usd/year to use unlimited. And maybe have a price per use only in the API.

edit: this pricing model also makes it expensive to learn to use the tool.