It is irritating, I've sold some things on there and people have done the same to me.
Some things I still have, because it wasn't the money I was after, just didn't need the item. But, like I said, it doesn't hurt to try, nothing ventured nothing gained. I have found that a lot of people need the money and they will sell if someone shows up with cash.
I have found many great deals on CL, and bought literally thousands of dollars worth of stuff for pennies on the dollar.
I bought an LD340 intake and a Weiand 8007 Action Plus for smallblocks on there for 50 bucks a piece.