i dont know about in dalas but where I live near and around calgary alberta canada there are no shells for sale, not many people stock them but the few things I could advise are to either make good friends with a chef or sous chef at a local high end resturant and ask if you can buy some shells or even stock off of them, the other thing that you could do is buy it from the person who offered to sell it to you in bigger batches make a big batch of stock and you can then freeze it. Either way you go make sure the shells and meat are fresh and dont smell of anything but maybe the fresh sea, kinda like seaweed. thanks.