It's a bit of a catch-22 because while Lemmy and the Sync for Lemmy userbase is small the dev needs to ask for more to keep the lights on.

If there was a larger pool of users who might potentially subscribe then the dev wouldn't have to charge as much.

But from a user perspective it might seem like a smaller/newer platform like Lemmy doesn't justify a higher cost.

For me personally I am happy to pay it because I used and loved Sync for years on Reddit and having had the experience with creating a Reddit app the dev has been able to provide a more complete/polished interface for Lemmy than possibly any other app available right now.