Its a huge price to pay...but it is absolutely worth it if he turns out to be a true franchise QB. Those guys can singlehandedly make teams contenders, and are few and far between, so their value is immeasurable.
Now, I am not nearly as convinced of RG3 as I am with Luck, but I commend the Redskins for playing a hand. If it works, the picks don't matter. If it doesn't work...well, they were going nowhere with their QBs anyways.