If his goal is $10 million then he'll probably end up settling for $8 million or $9 million. That's usually how goals work and there is some good competition in the pass rusher market.
To all the naysayers let me ask you this, if the Bengals offered us Geno Atkins for a can of tomato soup, would you want JS to take that offer? Because Geno Atkins makes $11 million per year on his current contract extension.
I think when factoring Bennett's versatility and consistency (as well as his extremely high PFF scores) I don't think it's a stretch to put Bennett at the same level, or perhaps very close to the same level, as Atkins. Bengals fans seem pretty happy to watch their team commit $11 million per year to him. Shouldn't we be happy to pay Bennett similar money? It's not like PC/JS have been mining pass rushers the same way they have churned out playmakers in the back seven.
I think if Bennett is obtainable for anything up to $11 million, Seattle should sign the deal and make sacrifices elsewhere. If he comes in at $8 million per, I'd consider it a bargain for whoever gets him.