I think it's an above average line when healthy. Last year they weren't. I think they keep Tretter unless someone bowls them over with an offer, and he walks after the season. He's good enough to be a starting center in this league, why wouldn't he sign somewhere that he can start and play? Barclay is on very thin ice, and I think he's basically insurance at this point. Do they really lose much if he gets beaten out by another player and is cut?
Rotheram, Walker and Taylor are guards. Not sure if Walker can play RT, and Rotheram is trying to learn C to be a swing guy like Tretter.

I'll say this much: if Sitton and Lang both go a la Wahle/Rivera, at least there are players in the pipeline who will get a shot at starting.

I don't think any of Barclay/Tretter/etc. would fetch more than a R6 or R7 just because a team can hold out for roster cuts or dig up some fossil on their last legs like the Packers did with Jeff Saturday.