Thanks for the sermon David , it is very helpful.
Thanks everyone for the other comments.
I have been looking online and it seems that the lego system addresses your point in that anything made from lego can be dismantled and rebuilt in a different form . There are lego train collectors out there doing that. I am thinking of a lego train system to be followed by an 00 scale set in a few years. The problem I see with LGB is our weather !!