try one of those online sources like prosper etc. 

Some must be using PriceLabs because it’s so common. 

Is there a contract that must be singed?

Hopefully, one of them can reach out to provide further assistance and insight into what you're trying to accomplish in real estate. 

.: I just hired an architect to design and plans submit for ADU in my 8 multi unit to use the tuck under parking.Some people say do not try to be the general contractor as it will take way more time, costly mistakes and will be nearly impossible to manage with current work. best to hire a company that will do it all and cost about $250 per square foot.

I am trying to get a second property via house hacking and have some questions for anyone who’s willing to answer.

Quote from @Nathan Nathan: It would help if you can explain what you have and what you are trying to accomplish.

@Brandon Blackmon Are you trying to figure out how much the GC is marking up your project?

Multiple people including myself have tried to caution him of the the true costs but he's been repeatedly dismissive and has made it clear we give him motivation and he wants to prove us all wrong (whatever that means). 

I don't believe anyone can look at how forests are managed and come to the conclusion it must be global warming.