Just send them all to me and you will have no worries.
But for real, my son had trains when he was small and loved them at the time, so here I sit with all of his trains when he is 38 and he still don't seem to care. Nor does his son. He moved on to Radio controlled cars, fast real cars, and girls. The only saving grace is the 3-year old grandson from the 27 year old daughter. How long will that last??? God only knows. I would just hold onto them if you don't need the money, someday you will retire and have nothing better to do than build a layout for you and the grand kids. Has worked for me. ;-)