sportshooters indoor gun range on 1st street has a used glock 19 for $475. Otherwise check out shooter's supply in Lyndon, or www.kyimports.com may have some used ones. If you can't find something good there, try Knob Creek Range.
I have a 3rd Gen Glock 22 I may be willing to sell/trade if you're interested. I live in St Matthews in Louisville, KY. lemme know via email or IM.