Happ Controls seems to be the place. www.happcontrols.com
No happs controls is definately not the place unless it's your last resort. They have a lot of nice products but are always overpriced.
Not
always.
Their horizontal microswitch buttons are currently on sale for 99 cents, plus an additional 2% off all online orders. (The ultimate joysticks are on sale, very cheap, too, but don't buy them.)
Of course, if it's not on sale it's higher priced than other places. And often even the sale items are still more expensive. So unless you are going to buy 26 buttons (to meet there $25 minimum), it is usually cheaper to buy elsewhere like Howard says.
However, I like checking out happs first for product information; they have better-then-most on-line info on their products. Then I know which products #s to look for and which to avoid when I buy elsewhere.