You need to donate 12$ as a single donation, it unfortunately does not "stack".
frustrating thing is, if someone paid $10 in the past, and was able to access the paid tier back then, they cant now.im equally disappointed that the developer has done this. Im just hoping this isnt to incentivize paying again. If so, they have lost my support.
Considering the lack of communication I do not see any other way to interpret this anymore.