If you are keeping the old machine, I would hang onto them :D:D:D If they fit the new machine, I would hang onto them LMBO Having extras of what I regularly use would not bother me one bit, especially the walking foot as they are spendy to replace.
Also it is nice sometimes to have both machines set up for doing different things so you can bounce back and forth, or have a second set up if a sewing/quilting buddy comes over :D:D:D