What is a proven franchise quarterback worth in trade?

Hypothetical scenario: Joe Flacco suffers a setback in his rehab and goes on PUP, and the Baltimore Ravens go into 2016 with Ryan Mallett as their starting quarterback. Mallett is playing so well that Trestman and Harbaugh just cannot bear to bench him. Mallett exceeds all of Flacco's regular season statistical benchmarks, showing great chemistry with the Ravens weapons, and takes the team to the playoffs. He wins 2 games, and the Ravens are suddenly left with a quarterback controversy on their hands. Mallett will be a unrestricted free agent, so the Ravens can let him leave and take a 3rd round compensatory pick, or they could franchise tag him and see what he would garner in trade.

Teams, sensing opportunity to add a real quarterback, are more interested in the more proven, locked in 31 year old Flacco than the 28 year old Mallett. What would the true value of a franchise quarterback like Flacco, whose floor seems to be average NFL starter with another gear in the playoffs?

With the exorbitant price paid by the Los Angeles Rams and Philadelphia Eagles for completely unproven franchise caliber players, it is an interesting question. The two benefits a player like Carson Wentz or Jared Goff presents which a more proven player like Flacco would not are youth, and cost controlled salary for the next 5 years. While Goff and Wentz will make about $26 million over the next 4 years, Flacco will make close to that in each of those years.

But Flacco also presents less risk. His value is undeniable, as there are teams like the Browns and Jets who have been unable to take the next step because of a lack of production at the position. Flacco on the other hand, has the most playoff wins of any quarterback not named Brady over the past 8 years, and a Super Bowl MVP award to his name.

To get an idea what quarterbacks go for these days, here is what the last 3 teams to trade for franchise quarterbacks in the draft gave up:

Philadelphia Eagles

Two 1st round picks (including #8), one 2nd round pick, one 3rd round pick, and a swap of a 2016 4th rounder for a 2017 4th rounder.

Los Angeles Rams

Two 1st round picks, two 2nd round picks, and two 3rd round picks (sent back 4th and 6th rounders).

Washington Redskins

Three 1st round picks (including #6) and one 2nd round pick.

These are quite the hauls and for quarterbacks who could end up unsuccessful in the NFL. Career backups like Matt Schaub and Kevin Kolb have garnered value in trade, as did Alex Smith, but none of them was traded for more than two 2nd rounders. The only comparison of a quarterback with significant NFL experience is Jay Cutler, who was traded by the Broncos to the Bears for Kyle Orton, two 1st round picks and a 3rd rounder.

So while Flacco is more expensive and a handful of years older than Carson Wentz and Jared Goff, he is a proven commodity with little bust potential for the acquiring team. What would that be worth to a team which feels it is on the cusp of contention? Is three 1st rounders and two 2nd rounders really so far fetched?

Let us know what you think in the comments!