Why would you not wear a $500 shoe? If you don't want to spend that much or can't afford to, that's fine. But, a shoe is a shoe. I have stuff I don't wear for various reasons, but price isn't one of them. If you are thinking they are investments - then you shouldn't be hesitant to buy them because even if you don't wear them, you are going to get a return on that investment. If you want to wear them, then you shouldn't really care about reducing their value by wearing them... and it's not like they become worthless when they are worn anyway. So, it doesn't make sense to me. If you want them for whatever reason and can afford them, it makes sense to buy them.
Where did you get the $75 DS Bucks from? Steals are to be found, but on the face it sounds sketchy.
To my knowledge, those methods don't really work long term.