I refrained from such a trade when my son was young...I had my eyes set on giving him a couple of nice handguns when he became 21 and on giving him others since then.
I found it much more fulfilling, (for both he and I) to see him receive a handgun as a right of passage into manhood. When he turned 21, I gave him an O.D Green CZ-P01 and a 4" Dan Wesson (Monson mfg) M-15, full lug. I was then able to accompany him to the LGS to help him pick out his first purchased pistol, an HK45.
Since, I traded him out of the DW, as he didn't like the trigger, so I took the DW back and gave him a S&W 686+ Mtn. Gun. This way he now has a full-size 7 shot to pair up w/ the S&W 386+ Night Guard, he purchased 4-5 yrs ago. (He and I both own 386 NGs)