Last year there were only a couple of tires sized 265/60/18. They were in the $110-140 range. You can buy cheap wheels in the $500-600 range, but sizes that fit a particular vehicle are hard to come by for a reasonable cost.
I had waited for over two months for a particular wheel. When again told that I still couldn't order them, I looked at other wheels again. I didn't find a perfect wheel, what I settled on is actually a Mercedes wheel, and the selling company charged me $30 each to remachine them to fit my Mercury. My wheels were $200 each, plus the $30.
Depending on your tastes, how you want them to fit, etc, you can get 18's for under $1000. Most people spend a lot more for wheels/tires that are over 17". Good luck,