The Eagles' decision this week to sign Sam Bradford to a two-year, $36 million contract wasn't a popular one among some fans. But the reality is that good quarterbacks are hard to come by and perhaps that, more than anything else -- including Bradford's lackluster stats -- was the driver of this deal.

Eagles executive VP of football operations Howie Roseman was much more diplomatic in his explanation of why Bradford was re-signed, but the underlying message remains the same.

“When you’re talking about a quarterback, there is no level that you won’t pay for a high performance for a quarterback,” Roseman told PFT Live. “In terms of the market and when you look at the options that are there to keep a player from free agency, whether it’s a franchise tag or transition tag, one-year deals, from our perspective we wanted to make sure it was more than a one-year deal so that we weren’t building our team just for this one year.

"We’re trying to look at it over a period of time as we build this team. So it was very important for us to get a multi-year deal, a deal longer than one year, and this was an area right now where you’re in a vacuum. Free agency hasn’t started, able to come to a decision and for us, and for us it’s about what is best for the Philadelphia Eagles not necessarily what’s best around the league.”

Roseman added: "We know how hard it is to find a quarterback."

And that, more than anything else, is the takeaway. Demand is the salary driver, and there's a scarcity of quarterbacks. That's great news for Bradford, who still has tons of potential but has yet to put it together on the field -- though others around the league are mystified by the Eagles' decision to bring Bradford back.

CBS Sports NFL Insider Jason La Canfora explains:

Bradford, who many executives and agents believed had little-to-no market outside of Philadelphia, received $22 million guaranteed for one year of work, and the chance to earn $36 million over the next two years (including about $4 million in incentives). This is the same Bradford whom the Rams, who drafted him first overall and remain one of the most quarterback-needy teams in the NFL, were eager to finally part with a year ago rather than have to pay him another $14 million to try to come back off another surgery and believed, ahem, [Nick] Foles to be a more viable option.

Sam Bradford will have at least another season in Philly to prove himself. (USATSI)
Sam Bradford will have at least another season in Philly to prove himself. (USATSI)

The problem for the Eagles is that there is no backup plan beyond Bradford, at least not one that's currently on the roster. In terms of average annual salary, Bradford ranks 16th, according to Spotrac.com, immediately behind Kirk Cousins, Ryan Tannehill, Colin Kaepernick, Jay Cutler, Tony Romo and Matthew Stafford.

Of those names, you might be able to argue that Bradford is better than Kaepernick but otherwise, he appears to be worth exactly what the Eagles paid him: middle-of-the-pack money.

Alternatively, the Eagles could have let Bradford walk and hoped that 25-year-old Brock Osweiler hit free agency. But in seven starts last season, Osweiler wasn't much better than Bradford; the former ranked 22nd in Football Outsiders' QB efficiency metric, the latter was 24th.

And while Osweiler is three years younger, he's looking at similar money to what Bradford just got with no promise of more production.

Other less-than-glamourous options includes kicking the tires on veteran Ryan Fitzpatrick (again, he'll probably command something in the $15-$18 million range). But as CBSSports.com's Sean Wagner-McGough writes, that would be a waste of money: "Fitzpatrick is not the Jets' quarterback cure. He's not their short-term plug for next season and he's not their long-term savior for the years beyond. Ryan Fitzpatrick is still Ryan Fitzpatrick, the antithesis of dependable, a synonym for inconsistent."

Then there's Chase Daniel, a former undrafted free agent who was Drew Brees' backup in New Orleans from 2009-2012 before signing with the Chiefs in 2013. He started two games in three years in Kansas City, and attempted just two passes last season.

Daniel's offensive coordinator was Doug Pederson, who is now the Eagles' new coach. And Pederson is convinced that Daniel, despite the lack of playing time, is a legit NFL starter.

"I think Chase, given an opportunity, yes, I think he can be (a starting quarterback)," Pederson told reporters at last month's combine, before the Bradford deal was announced. "People that have worked with him for the last three years know that he has an opportunity there and hopefully he gets his chance."

So why does Pederson have such a high opinion of Daniel?

"I think what he's done with Alex (Smith) behind the scenes, the way he's coached Alex, the way he prepares during the week, the way he studies, the way he puts himself in a starter's mentality on Sunday," Daniel said. "And then the couple games he did start there in Kansas City, to me, has proven that he can take over a team."

And maybe Daniel will, but it doesn't appear that opportunity will come in Philly, at least not this year.

Which brings us full circle on Bradford. The 2010 first-round pick is indistinguishable -- both in ability and price -- from other possible alternatives. Put another way: It's a seller's market and Bradford has the leverage. And when it's all said and done, he will have raked in $114 million in nine NFL seasons, and that's in light of some truly uninspiring football.