You'll be lucky to find a store that carries anything other than Groove Tubes. Why? because it's about moving inventory. 99% of people who buy tubes at local music stores will ask for Groove Tubes.
You might find some used old stock (you can test it to see if it's new) at some electrical equipment salvage places, and you might come away with a bargain. These will have come out of miltary equipment mostly. But it's a crap shoot, and very time consuming. 99% of it is picked over by people like you who go in and just want to spend the day sorting tubes for the guy, and you'll take home what you want for a pretty good price. They'll be loose and in a shoe box.
The NOS stuff has already been sold. Used are all that you'll find. How much is your time worth? Honestly, I wouldn't bother with NOS or used old stock in anything other than a clean module where the tone will be readily heard. Waste of money in high gain apps., and a lot of these tubes can't handle the high gain. You may be fantastically lucky to find a RCA black plate 12AX7 which I'd save for recording purposes only.