Except for this....
Any team giving up that much draft capital is going to want him signed long term beforehand, which would require Prescott agreeing to go to a place like Jacksonville....which is doubtful.
He can hold his ground, then you're not getting two firsts for a one year player who may not even report.
There seems to be this perception that the franchise tag situation can be turned into a trade without the full knowledge and cooperation of the player, and unless you're willing to accept pennies on the dollar in return, it cannot. Even in that case it may be difficult.
The easy way to capitalize in this manner would have been the use of the non exclusive tag, but the team chose to not go that route. They want the player, not picks.
They could give his agent permission to seek a trade, but that would be difficult to pull off, and Jerry doesnt play hardball with players because he wants to be liked...not to mention the small issue of the fact that he doesnt want to trade him.