The G-20 is a great choice!!!!! When I bought mine I didn't think I would like it because of the larger frame/grip and the hot loads, but it shoots better for me than the 22 or 31 that I had. My wife even wanted one after shooting mine (she's doing about 4" groups at 15 yards with very little experience and hot DT ammo! That's my girl!
). I got her one for Christmas (a bit early), and she loves it.
As far as price goes, you will probably be spending $550-600 on a NIB Glock 20. It will be worth every penny!
I think mine's probably valued at a little over $1000 right now, but that's with a trigger job, magwell, SS guide rod, ext. mag release, ext. slide catch, various aftermarket springs, sights (Trijicons on there right now, but a new set of TFO's sitting on the bench waiting to go back on), 6" Jarvis barrel, and a couple of other small parts. Everything that has been done has been worth it. That's the nice thing about the Glock- lots of goodies if you want, but you don't have to do anything to them if you don't want to.
With the 6" barrel the G-20 can do low-to-mid .41 mag ballistics with comparable bullet weights up to 230 grain. The 10mm can not touch the hot .41 mag stuff, but then again you can't carry 15+1 rounds of .41 in your wheel gun either!
As well, you can drop a sub-$100 conversion barrel in and shoot cheap .40 at the range all day long. Overall, and excellent choice! By far the most versatile handgun I have seen, and definitely the one I would choose if I could only have one handgun for several applications. You will not be disappointed!!!!!!!!!!