How much should I pay for Tuff wheel, button and adapter?

It is hard to find a nice original tuff wheel. I would have to take a look at it first. Some of the repop's are nice and some aren't. Just do your homework and get the better version. You are right about the adaptor. I just sold one for $100 and they still can be found at that price. You just have jump on them when they come up. Good Luck!