The need is there. There is an SA that does not sell gas on Thomas. It serves as a local store of a sort. There is another locally-owned store down the block that some neighbors wanted to close because they asked for a liquor license. Be aware of your clientele, don't piss 'em off.
Small stores can survive and thrive.
Uptown and Grand Avenue are rife with them. I suspect other parts of the city are too. Big box retailers are not the evil bad guys. They have more of what you may be looking for and bring products in that may never see shelf space in a neighborhood store. They were created, in part, inresponse to high prices and limited selection in smaller stores.