Seller riffraffgames has a large number of Sega Master System games up for grabs (100+). Nothing truly mind blowing, but worth a mention as many are very cheap and he is willing to combine shipping. They all end today, and the bulk of them are deep under $10.00. Lots only have their starting bid at $0.99.
My suggestion would be Enduro Racer – my favorite Sega Master System game of all time.