Bungie's transmog monetization definitely has a precedent from other MMO's. Most of them, though, use currency that is more plentiful and easier to get than synthweave. While it would be convenient to have all transmogs be free, I feel like that could almost cheapen the value of having a large collection of transmogs (although I'm sure I'm in the minority there). I think a good middle ground would be to charge bright dust or large amounts of glitter for each unlock, since those are much easier to acquire and do not have a cap on the amount that you can get for free in a season.