Serpstat - Content ideas from autocomplete suggestions

I just signed up and like the service. However here's a heads up to those who are looking to subscribe -- Their query based pricing makes the product almost unusable. They'll charge you for every DB query they post. Meaning for every click, your credit will drop by the amount of DB queries that action requires. For instance, one click costed me 15 credits and that's half the allowed daily credits, to give an idea.. More over, since they don't cache, if you click a report you just "purchased" they'll charge you again for the same report. Hope they'll improve this soon.

Hello, a question: purchasing Serpstat is the only cost to pay, or is there any additional cost (per search, per analysis etc.)? Thanks.