It'll be very hard. Likely the same goes for RGIII also. The way he's playing right now makes his cards pretty much as high as they will go.
Even if he plays well next year there will be a new rookie class with new guys people go nuts over.
Basically unless a guy goes on to be the next Manning, Brady or Rodgers, their cards will never be more expensive than there rookie year assuming they play well.
The only real invest to be made during a season is on rookie QBs that aren't starting yet. Just my opinion of course