Personally, I don't care if the negotiation is long and painful. Both times it ended up being a fair value contract for both sides. I expect the same once again for Barrie's third deal.
The reason it ended up being fair deals each time, is the same reason it could result in Barrie being moved, and the same reason the Avs don't get along that well with Newport. The Avs don't like to cave, and Newport doesn't like to either.
Newport/Barrie eventually had to cave each time. Otherwise they would have had to hold out entering Barrie's second real NHL season, which wouldn't have looked very good. Or take the arbitration ruling in the second negotiation, that pretty clearly was not the number they were hoping for.
So the reason it could be a problem next time is because Barrie and Newport don't have these consequences now. The Avs can't call their bluff because they're not bluffing. They can just go to UFA and get top dollar with a NMC. So now it's the Avs turn to either cave or not cave.
If both sides approach negotiations the same way, it will most likely not go well again, and the Avs will be faced with a decision to either hold onto Barrie his final season and continue to negotiate hoping they drop their asking price, or trade him the summer before.
If they go into his final season with him unsigned, they'd be taking a gamble that he won't get injured and he'll be healthy enough to move at the deadline for full price. Which could also be similar to the St Louis/Stastny situation, which could hurt the locker room and their chances at the playoffs. Plus just weakening the team in a playoff hunt.
Moving Barrie's rights after his final season shouldn't be an option because they'll get pennies on the dollar for him.
This is why speculating about what Barrie could return in trade, isn't the same as just being on a trade Barrie train. It's just looking at the history of both sides butting heads multiple times, and seeing the writing on the wall for that to potentially happen again.