my experience as a kid was that cheap boards were a real waste of money for the parents.
the quality of the wheels and bearings was so poor that the board made hard work of any poor surface and would stop at the sight of a stone.
hence the kids lost interest quickly and then wanted to try something else.
my first board was pretty decent at £60 back in the days of skate city, but it was quality and consequently I spent most of my waking hours on it.
Whereas the kids whose parents had spent £25 gave up and their parents could just kiss that £25 goodbye.