If you have a large mixed assortment of wines bought inexpensively over the years from the supermarket, you will find them almost impossible to sell. They are unlikely to have been cellared in ideal conditions, and many of them may be past their best. The majority of inexpensive wines are intended to be drunk soon after purchase, and will tire rapidly after two or three years in the bottle, so the market for such wines is all but nonexistent. Probably the best thing to do is throw a party for your friends and neighbours.