Ok, so here's a possible can of worms, after checking the cash shops of SWTOR and of GW2 I noticed how they have plenty of unique armor skins that you can apply to your gear, skins that are (at least in GW2's case) completely unobtainable in the game.
World of Warcraft also has a cash shop, it sells only pets and mounts, but what would you feel about if blizzard added transmog sets that can only be obtained via the cash shop? would you hate it? would you welcome that change and actually buy them?
I'm talking about 100% statless armor, sorta like the armors you get after you get Gold in all the challenge mode dungeons, just cosmetic armor with a unique look that, just like the mounts and pets offered in the cash shop, can't be obtained in any way on the game.
Same goes for weapons, if they added unique weapon skins for transmog that can't be obtained otherwise, except for the cash shop.
(Personally, I would hate it. Sure, they're optional, but for a lot of players, your own aesthetic is just as important (and sometimes MORE important) than stats. Most armor sets in the game look terrible, and if they suddenly develop a really REALLY good looking armor set, only to slap a real-money price tag on it, that would be almost insulting. This practice could be acceptable for F2P MMOs, because they have to make a profit from somewhere, but for a sub-based game, there is no excuse.)