Charles is sort of a tough guy to collect. He only has a couple certified auto's and GU cards and they go for big$$. Ewing is a little easier to find and has signed some stuff the past few years. I did here he was stopped signing again but I can't confirm it.
If I had money to spend I would buy Barkley stuff just because I really loved Barkley. He was my first real favorite player (2 years later it became MJ).