If you have a chance to trade for a young QB that you know is a sure thing, then its worth it. Luck is money in the bank at this point so I would go for that trade.
On the other hand, we have that situation in Washington where they used or gave up a total of 4 picks (3 firsts and 1 fourth) for 2 QBs back in 2012. And it doesn't look like they are anywhere near being set. They now have Colt McCoy as their starter.