Hey you're the one who's paying for pixels and code
^This. I would never buy extra RP. I still have the 400 RP I started with. Some random dude bought me a 975 RP skin, so that was cool, it is the only one I own. I don't intend on ever getting any other skins, unless I get a code or whatever.
RP is nothing compare to any of those rpg, $20+ for a mount/costume, then they release another set with 5% higher stats for even more. Not to mention their 'super rare' mount that you to need play lottery to win at a cost of 5% per spin(with undisclosed chance of winning, unlike real lottery, they could put it at 0.01%)