I never had this problem,I only ever buy transformers i would never get rid of..I do have a few sentimental ones i'd never get rid of.
my first transformer i ever bought with my own money,Beasts wars Optimus Primal .As for parents doing what yours did. I moved out of home when i was 18, which was around the time when Beast Wars came out, so i was able to spent my money on what ever i wanted without being told how to spend it. as for horror stories involving kids getting there grubby little mits on my Transformers, This doesn't happen in my house because if friends bring there kids over and the kids ask "can i play with the Transformers" The same answer is given every single time "NO because you didn't pay for them and i cant afford to replace them"I'm a fairly large guy so they only tend to ask once. Even my 3 year old son knows better than to ask after he broke my animated Bumblebee...my fault for letting him play with it,he has his own bumper bumblebee now so he doesn't to play with my toys....