Disclosure: I work for AnySystem.com (a Sun hardware vendor)
To be completely honest, no one beats ebay on prices.
However, be VERY careful about who you buy from, taking care to check their rating and their
recent feedback.
[FLUFF]
I once heard someone say (regarding ebay sellers) "eBay only works for people who don't understand what their true costs are." -- and he was right - the cost savings a consumer can find on eBay comes at a price: To run a reputable, reliable company that can consistently warrantee the products it sells takes money. If a company is continually selling things on eBay at razor thin (or non existent) margins, the only adaptation they can make is to become "hit and run" sellers - sell to someone, run away if any support issues come up.
I've had more than a few customers buy something on ebay after I had quoted them a higher price only to regret it after realizing
a) the item does not show up,
b) the item shows up, but is broken and the seller won't fix/replace it,
c) the item shows up with a different (usually lesser) config than what was advertised, or
d) the item shows up, works fine, is configured as advertised, but at some point the hardware fails and the seller is nowhere to be found.
[/FLUFF]
I've purchased stuff (even Sun stuff) on eBay, but I always thoroughly research the seller first.
Anyway, just my $0.02, but of course, I'm biased. . .
You'll have to take what I say with a grain of salt.