They didn't lowball him. The initial offer was 4.5 million, he got mad and took 6 million from Detroit. He didn't even dicker, just got mad and left. There's an interview on 710 where he calls in and says just that.
Good for him taking the extra money, but Detroit will always be Detroit, a bankrupt town with high crime and murder rates. They will have up and down seasons, mostly down now that Megatron is no longer impervious to injury.
It's on 7 days, a bad 7 days in Seattle, a good 7 days in Detroit, does not a lifetime make. We still own the Lombardi.