Maybe I'm misreading things, but I don't see Graham being perceived as a top TE. He seems like a solid player; a useful addition to a team but neither a game-changer nor irreplacable. Then again i would have said the same about Givens, and look at what he got.
This also seems a good place to mention another effect which could really help the Pats next offseason. They've lost some of their shine, enough so that people started picking the Dolphins to win the AFC East. If the Pats lose early in the playoffs other teams may stop the practice of overpaying for their players, which is what typically kills great teams. Of course, when the Pats win the superbowl again there will once again be a premium attached to every patriots free agent.
I see the success of the team having a large influence on the offers Graham gets next year. If the Pats have another disappointing season (hard to call last year a disappointment, but we're talking perception here, not reality) I see Graham receiving money closer to that of a #10 TE. A superbowl season probably sees Graham getting top 5 money as some team's splashy move.