Having paid $6 for reddit sync probably over a decade ago while the dev has maintained and improved the app over those years with no additional money from me, I think I got a pretty good deal. It's definitely a calculation to make but I don't think $20 would have been unreasonable a decade ago and I don't really think it is now. Maybe also dont forget to put some blame on reddit, the dev got fucked there and has to rebuild the customer base that would have included recurring payment customers (unlike me).