I bought my rack components used for a fraction of the cost of new ones. I got cradles so cheap ($75 for 4 pair) that it wasn't worth the effort to make my own.

Thule and Yakima have fitting info on their web sites. Figure out what you need and look for a rack with the right feet and crossbars. The fit kits are cheap, so you can just buy the one you need new.

One other brand of rack that looks really nice is Saris. However, they don't seem to be significantly cheaper, just easier to install and remove.