And if they would have known that Seattle was going to trade ahead of them, they no doubt would have.... And right now, I am sure that they wish that they had. But, guess what everyone has to make judgment calls in the draft. Can I get said player here or do I have to trade up to get him. All teams do it, and not all teams trade up all the time to get a player, sometimes it is smarter to stay put and hope a player falls to you.
The year we drafted Felix Jones, the Titans were planning on drafting him instead of Chris Johnson, but they rolled the dice that he would make it to them, but he didn't.
If Dallas had it to do over again, knowing that Seattle was going to trade up if they stayed put, would they have tried to trade up, I am sure they would have. But they took the gable, that they felt very safe about at the time, that noone ahead of them would take Unger. In this case they lost the gamble, because Seattle traded ahead of them to get Unger.
Same thing happened with Baltimore this year wanting Dez Bryant, they figured that New England would not take a WR #1. So they felt safe that Dez Bryant would make it to them at #25. What they didn't anticipate, was that Dallas would trade with New England to get Dez Bryant.
It isn't that Dallas wasn't willing to trade up to get a player, they just made a judgment call, that they didn't need to trade up to get Max Unger. They guessed wrong. But guess what, so has every other team done before. It happens.