For some reason it's surprisingly hard to figure out what these are currently going for.
I stumbled across a very clean/low round count one on a trade a year or so back, dropped in a Killer Innovations Velocity trigger shoe, SLR Rifleworks magwell, and 2x SLR mag extension baseplates for it (roughly $340 in parts). Problem is it's been a safe queen ever since I bought it and I have other stuff I'd rather have taking up space in the safe, plus I'm primarily stocked up with 9/45 and edc a 9 so this G20 is destined to never get used as long as I own it. Got a friend of a friend interested in the G20 but not sure what pricetag to put on it, it would have to sell w/ the upgrades because they're G20 Gen3 specific and useless to me elsewhere.