A good price on a NIB G21 is $550 with two 13 rd mags. That is for the fixed sight non compensated model.
That G21 is a fat mother. Most people find it doesn't fit their hands well. And the .45 ACP is a little expensive to shoot. Have you tried any other Glocks? I have a G34, G31 and G33. All great guns. The G34 by far the easiest to shoot well. Check out
www.glocktalk.com. For ammo its hard to beat walmart for .40 amd 9mm. Georgia Arms is a quality manufacturer of reloaded ammo. I have sent thousands of their rounds down range without problems. Good luck.
Paul