The hardest skill position to find is an outside WR who can create separation as there's a scarcity of those. That's why you see the elite one's making 30 plus million a year.
The market speaks when it comes to that. It's the easiest replaceable position on offense. Barkley could only average 3.9 ypc last year because the Giants o-line wasn't very good. Now he's averaging 6.1ypc because he's on a better o-line.