I am currently busy with the roof of the matriarch of one of my closest friend's family. It was roofed less than five fucking years ago and has had problems ever since - problems that have gotten increasingly worse. I have finally gotten around to taking it apart - days before my fall semester starts - and what I have found is verging on fucking criminal. These assholes made mistakes on this roof that were obvious enough, that I doubt a single reader of this blog would not have recognized them as major fuckups.
If you get a bid for work on your home - especially the roof, electric or plumbing, that is more than fifteen to twenty percent lower than the next lowest bid (assuming the next was from a yellow pages, licensed contractor - most states require the license number on any adverts) don't go there. Do not get excited at the notion of saving big money, because when you have to hire someone else to come along and fix everything that got fucked up (or in the case of electric, burned up) you are going to lose those savings and some. It is expensive to get that shit taken care of later - so just don't fucking do it.
At the very least, someone working for that much less is not carrying insurance. There is simply no way that someone can actually charge that little and be covering necessary overhead. In some states an exception might be a licensed handyperson, but if you are talking about a relatively large job, that work won't be covered by the handyperson's insurance - though again, there are some exceptions. But, even as someone who used to work as a handyperson, it is just not worth the risk. I hate to say it, because I was perfectly capable of jobs that I took on - I did what my clients wanted and at a reasonable price. But in that, I was exceptional. For every one of the people like me out there, there are a few dozen who are just going to fuck your shit up...
Sorry it has to be like that, but that is reality.