I shipped a set of 18" Roush wheels with tires mounted on the from DC to LA for $45 per wheel by UPS. I think FedEx actually had the best price @ $37, but I was in a hurry and went to the UPS store next to my house for convenience. Covered the "good" face of each wheel with cardboard and then shrink wrapped each one with a 6" wide roll of the stuff from Office Depot ($5-$7). One roll was plenty.
2006 E90 325i - Sparkling Graphite