Materials will be about the same, but labor may vary greatly on location.

Hiring someone to do the work will likely cost too much (I would charge a small fortune, it's an incredible amount of work) and doing things as cheaply as possible will bite you in the *** later when you start having issues with your own shoddy work and/or materials.

ACM (Asbestos Containing Material) abatement is a tough one because often you won't know (outside pipe insulation & 8x8 tiles which I can spot and point out with no testing).

As well as utilizing them to market and sell your properties.

I believe you can also utilize an independent savings account, but you should check with the bank to make sure.

Because it's a material fact to them.

You can expect that you will be required to build roads, sidewalks, storm water control, utility taps, street lights, street trees as well as recreation fees as part of the development process. 

. $50k sounds like a lot to you but with the price of materials and of qualified labor, it does not go too far.

I would have been ok with the latter numbers because I have been stockpiling materials for like two months, but...I did not know if I could trust them due to the lack of "professionalism," and my lack of experience. 

It is very competitive but if you utilize good resources and think smart you can do really well!!