#not_all_contractors_are_shady :)
Anyway long story short it sounds like you have the classic example of the contractor who isn't so strong on the business end. What that would mean in your shoes is you might have to baby sit him a bit and be on top of a few things he probably should be. If you feel he is a good trustworthy contractor that will complete the work in a professional matter and you have a good relationship with him it might be worth it. If you're too busy to be checking on his permits and making sure what he says is getting done is getting done (and done right) then I'd strongly consider one of the other contractors.
I normally don't do itemized bids either. It's too competitive around here and people try to take advantage of contractors just as much as contractors try to take advantage of people (sad really on both ends). So I simply say this is the job you asked me to quote, this is my price for everything. I don't change that price "to beat the other guy" either. If he's cheaper fantastic hopefully he knows what he's doing too.
Whether or not he should still have a shot comes down to your choice really. Have you worked with him before? Is he a quality worker? Is he efficient? Are any of the other contractors highly recommended and possibly a better option?