I would say ebay is your best bet, they have just about every version and you can often times find fairly good deals! Amazon has a few tamas with prices ranging from standard to too much so I wouldn't highly recommend it although they are a very trustworthy site. Next if you're looking for Japanese websites try cd Japan or hobby link Japan or ami ami they often have good deals but also have limited stocks and go out of stock often... Now as people have said most store don't carry tamas if any did it would be a flea market of sorts or like a second hand shop.