Charging to "support" the game is one thing, charging to gain an advantage is quite another.
I've spent a reasonable amount on games that I don't have to (games that I can find free download of, skins and other cosmetic item in various game, in fact there is this one game I bought that I will likely never play because I liked their art style and anime spin off) and items of the sort for primarily the reason of supporting the developer.
I have never spent a cent in a ptw game, for multiple reasons.
That's not to say I didn't spend money on games where it carries game play benefit, but none of those were gameplay wise significant and was not the reason I spent in the first place.
That, my friend, is the difference between "supporting" a game and "ptw" a game. Which one are you?