Somewhere in SLC where I can buy cheap, retro video games?

I just bought a cheap (and hopefully not too crappy) NES, SNES, and Sega Genesis combo console. Unfortunately, I don't have any games for it yet. I've been looking around on Ebay and Amazon, but haven't been able to find all the games I want for a good price. Plus, I just want to go to a video game store and browse the titles. Is there anywhere in the SLC area that sells used NES, SNES, and/or Genesis games? The only place I came up with on Google is Play N Trade; is that worth checking out? Where else?