It's really tough to answer tbh. I think it's going to be more profitable long term to own a store, but maybe early in the game, breeders and owners deciding to sell Legendary dogs might make more. Stores will be able to sell skins in the future, which will also be a high demand item that will make you coin. You really cant go wrong either way, but if you can afford the 20k TRX, I'd say go for it!
RE: TRX TRON DOGS? What Are Pet Stores?