I've thought for a long time unlimited projects for free was too good to be true, looks like marvels pricing is more inline with InVision with only 2 active projects on the free plan
Kinda late, right? With tools getting prototype support inside the app there is no much space for tools like Marvel.
Marvel have announced they're working on Prototyping inside Sketch... I'm suspect the pro price might be timed with that release.
Aimed at Sketch users who need slightly more advanced prototyping (sticky headers and scroll to anchor). If so, pay for marvel, at least until Sketch has advanced prototyping. ¯_(ツ)_/¯