I would argue the exact opposite, that he is highly over-valued on this board.
Possibly, but look at some of the contracts given to defensive centers. Darko almost got the MLE, and he's terrible. Haywood got more than the MLE. Varejao got more than the MLE, as did Dalembert, and Biedrins, and Chandler. Pryzbilla got at least the MLE, as did Jeff Foster. Dampier got more than the MLE on his last contract.
I'd put all of those guys in the same relative range as Perk, with some obviously being better than others. I think the established market for players of that caliber is firmly over the MLE.
Now, things could change, due to Perk's health and/or the new CBA. However, as things stand now, I think he's established himself in the above-MLE range.
In terms of what we could get in a trade, who knows? I'd say he'd probably bring back a draft pick in the middle-third of the first round (even injured and as a pending FA), but that's pure conjecture.