There's several other flea markets:There is the Mission Flea Market. It sells mostly used stuff. The market has a couple of covered rows. The isles / rows are dirt. Here is their website.
http://www.missionfleamarket.net/There is also Eisenhauer Road Flea Market.
Eisenhauer Market Center - San Antonio's Largest Indoor Market a converted store so it's inside and air conditioned. As previously stated there is the Hwy 16 Flea Market or Flea Mart. I couldn't find their web site but it sells mostly new stuff. Has covered and paved isles/rows. They also have many garage type spaces for rent where you can lock and store your stuff there each weekend. Here is some info about it from the net, "Flea Mart. 12280 Highway 16 South. Hours 10am-6pm. Admission charge $1. Ample parking. Average weekend attendance 25,000. Approximately 600 dealers. Outdoor market with covered spaces. Great selection of goods here. Various types of food here for hungry shoppers. Clean rest rooms. The market has live entertainment, live music & many family activities. Space from $40. per weekend. Camping available. c/p Tom Browning, 12280 hwy 16 South. 78224. (210) 624-2666."Sorry I can't think of anything to give you advice on what to sell. I normally go to Flea Markets to sell my old junk instead of having a garage sell.