I ordered some parts from Ultimarc in the past (several sets of buttons, several joysticks, wiz keyboard encoder). They have a lot of stuff to browse and competitive prices, but I just can't get past their shipping, which has forced me to search for more local options.
I only have one complaint, and it appears to be an issue with almost all sellers. All the joysticks I ordered came loose and several had bent connections. They bent all back into place and worked fine, but I still don't like it. It was such a minor issue I never brought it up. Out of sheet curiosity, do vendors also get all their parts loose like that?