Which speakers are you looking at?
Some sites I can think of off the top of my head are:
thezeb.com
ikesound.com
woofersetc.com
discountjungle.net
sonicelectronix.com
What I usually do is find the product for cheap, even from a sketchy non authorized site, then price match through a site like sounddomain.com to make sure you get an authorized product.
I know there are some other good sites to check but I'm not coming up with them right now. Or you can plug the product number into a site like nextag or similar.