I agree with that, but it's not a uniquely Saints issue, it's a league marketplace issue. Teams have to overpay for average QB's who aren't on rookie contracts.
Take a look at how many QB's still on rookie contracts who were starters in the Super Bowl compared to those QB's in the Super Bowl who weren't on rookie contracts. That's a big part of why FA QB's are overpaid.
For a little perspective on the idea that their are QB's that can will their team to victory:
- Tom Brady played 23 seasons. He had 10 Super Bowl appearences won 7 and lost 3.
- Drew Brees played 20 seasons. He had 1 Super Bowl appearence and won it.
- Patrick Mahomes has played 7 seasons as a starter. He has been to the Super Bowl 5 times and he won 3 and lost 2.
If those guys can't consistently will their teams to victory all by themselves, then no QB can. It's a myth that a QB can will their team to victory. The better a QB is the better the chance the team has of winning, but the QB alone can not win a game. If they could, why bother having the other 52 guys on the roster?
Now, the converse is also true. The worst your QB is the less chance you have at winning games, even if the rest of the team is average. That's why all QB's are so highly valued. An average QB on a solid team gives you a better chance of winning than an all time great QB on a below average team. Just look at Brees's career if you want an example.
I'm not saying it's good that QB's are so highly paid. I'm just explaining why.