Here's a link to the highest paid wide receivers in the league this year. Note a few of these are "franchise tag" deals.
Vincent Jackson, you'll see, did get Larry Fitzgerald money. And he played well this year, too. Averaging more than 19 yards per reception for 1,300 yards, despite missing a game.
Wallace is worth a deal more in the $8-10 million range, probably closer to $10 million. If you want a player of his caliber, that's what they cost. He's every bit the player Santonio Holmes is, in my view. Pittsburgh used him sort of one dimensionally but he has a ton of versatility. Jennings for his part would cost less but not as much less as people think. Probably in the $6 to $7 million range annually.