If he had real, actual offers that he could have signed on the line for, we would have heard about it from the team(s), officially or unofficially. Did we even hear of him visiting anywhere? I don't remember even any rumors that he did, but there may have been.
I suspect it was more that his agent talked to some teams, the teams said they might be interested in him at 2-3M per year, but no actual offer was ever made, and he never visited there. In agent/player speak, these become "deals" he could have had.
I suspect Raji was waiting for injuries, retirements and suspensions to open up the market for experienced, but young DTs with warts on their resumes. You never know when lightening, or the reincarnation of of Al Davis might strike, and a team in panic offers a better deal than expected. GB needed to offer enough to out-weigh whatever chance Raji thought there was for that, and even allow him to save face, a bit.