speedandstyle.com usually has good deals like that too
but the main reason that theyre so cheap is because...velox rims are cheap.
Tires- yokos are good (a buddy of mine has em)
You should look at all qualities of a tire, wet/dry traction, wear, noise, stickiness, etc. I think
www.tires.com has charts like that.
EDIT**by cheap I meant inexpensive, not necessarily poor quality...sorry