I think now is a great time to remind everyone, like sync’s developer, Lemmy’s developers need to be paid too! The amount of time all the devs put into making lemmy exist, in my opinion, should be worth some of your money. If you can afford it, donating to the people who develop lemmy and/or the people keeping your home instance up will accelerate the incredible growth of lemmy!
I mean, that’s a problem with a “lifetime” purchase of anything, especially software.
But as long as your expected usage over your expected period of time is cheaper than a recurring subscription for the same period of time.
The true “lifetime purchase” for software, is the GPL.