It's allways better to know what you are getting involved in. There are many jobs that are better to walk away from than to ever start.
Just like playing poker it's better to fold many hands before putting much in the Kitty.
Contractors don't normally walk away from work that pays so right off you have a "Red Flag".
I did one of these jobs about a year ago. Someone did the ruff and supposedly the owner fired him.
Not sure what went on, maybe a little of each side. What I do know is the guy ran all the homeruns and didn't mark any of them.
Also, I couldn't find a couple of them. I broke out my toner and found them just dead ended hanging under the house, connected to nothing.
I told the owner to start with that I would do this on T&M. He didn't like that much and wanted a price. I tried to come up with a worst case scenario price and he didn't like that either.
Finally he said go ahead with the T&M. He said he and one of his guys would help to keep the hours down. I didn't like that but reluctantly agreed.
After I was finished, the total T&M was more than the set price I gave him. This was mostly because they neither one knew what they were doing and I had to constantly stop what I was doing and show/help them.
Also, when I powered up everything, there were a couple of circuits that only part of them worked. I found some buried boxes behind the sheetrock that weren't tied in.
So I learned from that if I ever (doubt it) do that kind of job again, it will be T&M or not at all!