[asid61]

Personally I love Ebay for almost everything. I ahve bought several Aduino clones, tons of pin headers for breadboarding (as well as breadboards), tons and tons of ICs, used Mitutoyo calipers, micrometers... the great majority of everything I own is from Ebay actually.
That being said, for FRC I wouldn't use Ebay. The shipping times can be relatively fast (~3 days max if you I from the USA), however, if a part breaks (which they do) you need to wait at least another 4 days to get another part. I have gotten refunds or replacements for 100% of the items which have broken (in one case I actualy ended up with a refund AND parts which I later fixed...) but because the parts are for hobbies I have no time limit. Support is fantastic, but you still need to recognize that breakages can and will happen on a relatively large percentage of parts (still like 1%) and if it happens at competition, that could be disastrous. For simple stuff like decorative leds it should be fine, but stuff like cables or sensors can go bad pretty easily (particularly cables; of a 40 pack of jumpers for breadboard there's always one or two that fail).
My $0.02.