Funny you should say "consistent stock". I've had the worst time getting parts from Wico than any other arcade parts vendor. Whenever I've placed orders, at least 2 or 3 items out of 10 were out of stock and had to be back ordered. I've been waiting for some backordered pinball switches for over 4 months now, and every time I call, they are still out of stock. I'm glad I'm not in a hurry for them....
I don't know about their arcade pushbuttons, maybe they keep those readily onhand.
As far as ordering as an individual, no problem. No minimum either, I think.... I always have the same problem as u_rebel, I order too much.