Less than $8M probably. He's maybe "worth" more than that, but there's a big opportunity cost to signing him to a bigtime "core player" keystone deal. It means...he's one of "The Guys" you're deciding to build around - and i just wouldn't want to do that. Cliched as it is to say, i just don't think he's a "winner".
So the deal would have to be under ~$8M in the sense that you can afford to have a secondary/supporting winger at that price point. But he's obviously not going to sign for anything close to that little.