The one I have is tied to a zero balance sweep checking account, so in the meantime I can park savings and idle banking funds on my balance, saving me a ton of interest cost.

So they still get a cut of my commission.

We worry he will take any additional payment, not perform the work, not purchase materials, and not pay plumber (who can tie up our project permits).

We haven't sold anything because in my view it's like cutting your cow into steaks.

@Chris Cambridge I know your probably wondering why it’s so last minute lol it’s because the bank that I was going to use wanted 60k down payment and I do not want to tie up that much capital on a rental.

I think house-hacking is still an amazing way to build wealth and cut your expenses with very little downside, its how I got started investing and if I wasn't married I'd be doing it to this day.I would consider how you feel living in the city above which one is best for house-hacking, all of them work.

There are options where you don't attach the rehab money to loan which in turn would cut the origination costs considerably.

This person, being a lawyer has all the time in the world to just tie me up in legal battles.

The reason no one will be able to give you an average cost (in my opinion) is because we have no info on what lines are needed, how far they are going, what floor is this on, is there a stack near by to tie into or a new line run all the way to the main for drain etc. 

Now, financing the entire build with your own funds ties up a lot of your capital.