Grip is really the only reason to have them so in my opinion that is the performance to judge them by. Like anything else there are scales like material (leather, faux leather), some have mesh for breathability, some have extra padding. As long as my daughter likes the feel and the fit is right we go with it. The last couple of sets we've gotten were in the $20 range per pair.
Thanks everyone. I appreciate it. I've seen some with a "protective" thin insert shield that cost $40. I didn't want to spend that much if I didn't have to.
I tend to agree with the feel and fit advice. I'm always willing to pay a little more for the better fit/feel, but I don't have a specific favorite to recommend. One thing to check is thumb fit: have DD put the glove on an spread her thumb and index finger as wide as possible; then check for air space between the glove and the skin between the thumb and index finger. Airspace there is bad.