As far as pricing goes, I'm positive that
www.tirerack.com has these available, as well as
www.discounttiredirect.com. Another option to find where to look for rims on the net, is by buying any import magazine, and checking out the links suggested in advertisements.
Edit: Also, the cost of an entire wheel/tire combo, is really dependant on the kind of tires you select. You can get more expensive rims, but keep the overall cost down by choosing less expensive rubber. You'll need to answer this question: What is more important to you: the look of rims? or the grip of the rubber?