Worked Saturday instead of Sunday this time. Seemed to be fairly well attended, but I didn't see a huge amount of money changing hands. If you're looking for a gun, it seems like a favorable time.
Problem is that after the buying panic in the first half of the year, people are now worried about being employed in the first half of next year, and aren't buying as much. Notable observation was the large number of people carrying guns to sell. If what you're looking for seems hard to find, I'd say wait till next month, then check the pawn shops.