I've never sold to Cameta, but I have sold to KEH. KEH is fair, but you have to consider the situation you're in. If you're selling to someone who is planning to resell your gear, you will not make as much money as you will selling to someone who is planning to use the gear. It's just like a used car; trade in vs. selling on your own. Ebay is more hassle, and possibly more risk, but there's also a potentially larger pay off. KEH and probably any other respectable reseller is a sure thing, but with a smaller pay out. It's kind of a personal decision. What are you more comfortable with?

Paul