I'd rather that not go that route as I'm rather cheap (and have concerns about it being p2w under the pretense of glamour being the real endgame), but with that said, it is certainly possible. And I do think that if they do decide to sell it then 5 plates and 200 additional slots would be fair for 2$ a month.

That said I think it would be better to have 30 free plates first (1 for each class and some left over) and upgrade that number to account for later Jobs, while targeting paid upgrade to those that prefer to change up glams for the same job constantly.