These are not veteran bigs. They have to be drafted first, then play in the league a few years.
I'm honestly trying to understand your point, so what team would trade their prized 1st rounder for Bradley/Crowder?
A team would absolutely trade their 1st for one of those guys. A team like Minnesota is begging for a guy like Bradley, ditto for someone like Indiana. Think George Hill to Indiana several years back, that's a similar trade to what KGLL is suggesting.
I think both could get more back, particular if Paul George becomes available. I think that if we add a big this summer that is not Blake Griffin then it'll be someone of the Robin Lopez mould but a lot cheaper. We need someone who can bang with the big centers of the league, won't mind low playing time and is cheap. If we can't find that then I'm absolutely fine with keeping Amir and having Zizic learn off of the bench.