www.superbiiz.com
California based. So sales tax if you live in CA but they have deals.
www.buy.com
they have a website and they have an ebay site. I just purchased an intel series 520 180gb ssd for 299 after promos 280
www.amazon.com
but tricky and they have bad specs on the gear in that no info is common. also second party sellers can be terrible.
www.jr.com
I got kingston 4gb 1600 hyperX sticks for 13 dollars.
WWW.newegg.com and
www.chiefvalue.com
its sister site are good but they charge NJ and CA sales tax still I buy 4 or 5k a year in parts from them
www.microcenter.com if you are close enough to drive to a store have the best cpu + mobo deals.
also dell hp and apple have sales on the net. certain times the deals are good.
for instance when in stock online an apple refurbished mac mini server is 850 no one tops that price.
http://store.apple.com/us/product/FC936LL/A
then buy parts from one of the other stores to boost the ram and swap in an ssd.