Problem is, you go cheap and get something that doesn't fit or has harsh recoil, I guarantee he will quit.
I understand what you're saying, but I will offer a different perspective...most kids can't tell the difference between a high quality piece and an entry-level gun. The refinements are going to be more appreciated by someone who is experienced. I would think either is sufficient for a middle-schooler getting into the sport.
Besides, what does he have to look forward in life if he's an 11 year-old with a Benelli Montefeltro?
Patriot, I think we have to define "cheap"... I agree, my son wouldn't get a Montefeltro, as I don't have one! But most of the time that I talk to fathers who are looking for a shotgun for their child, they are looking for a reliable, soft shooting gas gun for about $300...
If the budget is around $600, the Weatherby can be had, and it gets good reviews. I bought my son a Beretta A300... but it is 12 ga., and he was a little older when we purchased it.