That sounds like a great way to teach your son the meaning of value, nice work :D
and it seems to have worked. we were looking at toys in passing. and when i pointed out the quality of the material of one particular toy that he was looking at, he agreed, and said he didn't want it anyways.
he may soon be ready for a new brick set then...
i once bet my son that the toy he wanted so badly would not survive two weeks. and if i won, he'd have to promise me to never ask for junk toys again, but focus on lego and compatibles.
the toy survived 3 weeks.