I haven't been to Big Town in several years. It used to be a decent show but I can't say now. Market Hall is later this month and I will be going to it.
Dallas Market Hall is 9/26 - 9/27 and is a much larger show. If you need to renew, join or extend your NRA membership, you can do it at the show for $25 and you get free admission to the show.
Had started to go to Big Town, but a PC support call had be change plans. However, I think Big Town is a better show that Market Hall if you are a buyer, rather than a looker. Also, BT has more reloading supplies.