I have never spent money on cosmetic DLC and even if I did, I can't imagine I would ever spend more than $5.
That said, if other people want to spend money on it, and the company is being transparent and isn't using manipulative tactics to make people buy it, I see nothing wrong with it. I may think it's a bad deal but if other people want to buy it, that's their business.
"It's Dyin' time."
Captain Bruce Diehard,
Die Hard