Non-sports commons sell OK. You will see lots of people looking over checklists to see if they need something. Movie license games sell well, no matter how common or bad the game is. I remember selling a copy of Back to the Future (NES) to a guy who said "I remember this game! It's horrible!" And then he bought it.
I wouldn't price my commons above $2.
I have a great idea for vendors to get rid of commons (I have tons). How about a grab bag? We have a few rare or valuable games in a big grab bag filled with commons. We charge $3-4. per grab. The grabber keeps whatever game they pull out. If we have some good prizes, you can have a "proxy" in the bag for the prize. There's tons of ways to spin it. You end up giving out some great stuff, while gaining a little compensation for your commons.
Just an idea...