The St. George/Santa Clara area has experienced phenomenal growth in recent (15-30) years. The area does get very warm (triple digits) during the summer, but the trade off is mild winters.
Make sure you do a little research and steer clear of any place near what looks like a dry river bed. It may look dry "now", but will quickly swell during a flash flood. A couple of years ago, several homes were lost due to flooding. Seems weird to discuss flooding in the desert, but it happens.
Also a tad further north is Hurricane (pronounced "her-i-cn") It's an up and comer that is developing rapidly - like what Saint George looked like several years ago. My guess is that land/home values may be slightly less there, buy maybe not a whole lot less.
Good luck in your search!