I started in trains 40 years ago when my kids were small. I started with my childhood Marx 999 set and bought use postwar gear. MPC just came out with newer trains like the small Hudson Southern Pacific. I just stayed with post war. I saw no need to upgrade with kids doing most of the running and I never have been bitten with the new train bug and the "have to have bug. I often will make a car if it is not available at my price and find building cars and accessories one of my most enjoyable parts of the hobby. One example is my $10 homemade train turntable I have written about here years ago. Rational that is just me and I glad many are buying new trains to help the hobby grow.
Charlie