I bought the Harbor Freight Portable Tire Changer for $36 through the InsideTrack Club and their tire spreader for $20.
I have the HF Tire changer, and although it does work, it is HARD on your wheels. If you don't mind your wheels getting all scratched up, it is good.
I also figure that you need to get them balanced when your done anyway, so might as well pay the extra few dollars to have them mount them too. Around here, it is $7.50 for balance, or $10 for mount and balance.
Dave W