I am happy with the one below (nothing too fancy). It runs on my BlackBerry. It is as accurate as the phone's GPS which is better than me. I have found the yardage matches up with expensive units when I play with other folks. If I recall it was $29'ish. No maintenance fees, no cost at all after purchase, unless you change phones. Details on the web site:
http://www.nrange.com
My buddy got an app for his Droid for $10 which did the same ..
If I was to spend hundreds of dollars to know my yardage, I would get a laser range finder where I could get yardage no matter where I am. i.e., driving range. It is accurate to one yard, just my opinion....