You can try the Rockets Shop at Toyota Center. I'm not sure what the hours are but they are open before games and then they close when ever the Toyota Center's doors open. Then you will need a ticket to get in.
He I bought a "foil" alonzon morning for 12.5 cents in a corner vending machine, I was sure it wasn't legit
dauum, if you really want some baskeball cards, look up in the yellow pages. You might be able to find a sports collectible shop near you. It's definitely harder now since most hobby shops, (sports collectible, comic and etc.) are slowly shutting down due to the recession and people unwillingness to spend on these luxuries.