I wouldnt go to Play it again sports....overpriced for used crap.
I would however scour craigslist weekly. Probably your best bet at getting gear for a good price...probably being sold by some parent who shelled out a bunch of dough for hockey equipment for their kid who pllayed guitar hero once or twice and now wants to be Eddie Van Halen.
i highly doubt he's gonna learn that much as a kid to a point where he needs to unlearn things to ice skate. i've been playing roller all my life and i was able to switch to ice instantly. i don't regret playing roller as a kid, but i'll never go back now as long as i can afford it.
and a lower investment is a good idea for kids because they change their minds very often. but hey it's not my money....