I agree. While $20 could still be seen as reasonable - even though making it one of the more expensive apps, thigh I'm willing to go for it if Sync continues development -, the asking price of $100 for the lifetime ultra is insane. I'm not aware of any other app that is this expensive. Of course, you could argue there's subscription apps out there that don't even have a lifetime model - e.g. Adobe, Microsoft Office -, But these provide considerably more value as well and are huge corporations.

My feeling is - and I don't have facts to prove it - that the developers of the large reddit apps (esp. Apollo) simply became used to the money making machine and want to squeeze as much as possible out of it.

While in the end it is entirely up to them, as there's open source and free alternatives out there, I'm not too fond of this behavior.