I may be in the minority on this but...
Boston sent Al Jefferson, Ryan Gomes, Gerald Green, Theo Ratliff, Sebastian Telfair and two 2009 first-round picks to the Minnesota Timberwolves for Kevin Garnett.
Nets trade: Alonzo Mourning, Aaron Williams, Eric Williams, two first-round draft picks (2005, 2006). Nets acquire: Vince Carter
McGrady was never traded for more than a few 1st rounders...
I realize these are just a few examples and they occurred a long time ago but aren't draft picks still worth at least as much as they were back then in the early to mid-2000's? If not - how come? Teams still only get 1 first rounder and 1 second per year to rebuild their rosters. Unless that changes I'm not sure why 2 top 15 players in KG and Carter would command 2 and Donovan commands 6 or 7 first rounders. Crazy IMO!
Relative to the time - KG and Carter were both top players known for their offensive output. They were also known for being really, really good but not at that next level where you build your entire team around (eg Kobe). KG was close though. That sounds like Donovan currently to me.
My point is - why would we consider giving 5-6 1st round picks for a talented player that doesn't reach the upper level. Some say because you need him to get another better player to join. If that's true - then shouldn't we keep as many players/picks for that player if Mitchell is going to command 6 1st rounders - what would a better player command? I understand this way of thinking would likely result in another team giving more picks and outbidding us - but maybe that's better because value is still value. Just because Ainge fleeced Minnesota doesn't mean we should adjust to it and overpay so much.
For me 3 1st rounders + Fournier (or D.Rose) and IQ would be my limit. You can substitute Cam, McBride, etc...
Anything more would be an overpay. And yes... stay off my lawn!