I bought an alpine 5 channel amp off there, and the guy advertised it as being able to run 4 door speakers and sub. When I get it, come to find out you have to use an specific alpine head unit, and have a special optical cable to connect the two.

He said I should resell it, I was like nope, filed a paypal dispute and he lost. That's the only bad experience I have had, but I do look at seller feedback. And there are certain things on there I probably would avoid, like Leupold scopes, due to the faking.