The only problem with race specific equipment would be if you are wearing it when you change race. In which all SE would need to do is when you change race unequip all your gear. You can already own race specific gear on a character who isn't that race, or gender even, by mailing them from a mule that is that race or gender. Not exactly a game changer.

I imagine if they would have you pay for race changes it would be similar to how changing servers work in which case that microtransaction system is already in place. As for the tech to do it wouldn't that just be the same character creation screen when you first make a character?

That being said I'm sure there are thousands of people who want to change their character's appearance. I don't, but I think it should be something that is available.