My wife has an OD green Gen 3 G31. She really wants my 21SF to carry at work. A guy she works with wants to trade her a new Gen 4 21 for her 31. She is not a big fan of the Gen 4 grip texture. I will be replacing my 21SF with a 1911 for duty use shortly and was going to give her my 21SF and trade off her OD 31 for a new toy. My question is, would the OD 31 or the Gen 4 21 be easier to trade/sell. I know the OD's are hard to come by.