He's going to want to do takeoffs, he's going to want to size your mechanical equipment appropriately, he's going to want to make sure that stuff that he's not touching is up to code so that he can pass inspections, he's going to want to get an idea of the finish materials you what used and research pricing, etc.Then he'll probably spend at least an hour writing it up in a format that is consumable by you and your lender.These are all the things that you are just ballparking, and if you're off by a couple thousand dollars one way or the other, it's not a big deal because you have a larger profit built-in. 

Because they have a real estate license, they are usually held to a higher standard than a consumer, so they will not be able to claim igorance of real estate laws and regulations.

They wouldn’t be the first scam tag team in this arena .That said here is an agency to file a complaint with Consumer Financial Protection Bureau https://www.consumerfinance.gov/complaint/they are oversight for any licensed lender.If your “ lender “ was not licensed CFPB would advise you of alternative routes to take.

The seller may still opt for the buyer who is using a conventional option. 

If your intent is to have a legitimate transaction, then a contract protects both the consumer and the contractor.Most good contractors would be weary of a customer who refused to sign a contract for a medium to large sized job.

A few years ago I had 3 cars paid off (don’t generally like or carry any consumer debt), so I did cashout loans on them and sourced about $50K cash on them at like 3-4%.  

Few years ago I started feeling there is a need to earn more to support our growing needs perhaps with a second job but that would take away my personal time with my family .I got inspired with my previous landlord who was house hacking with a multifamily, started researching BP and started devouring every resource that came my way and took a big leap of faith and invested in my first multifamily without getting stuck in an analysis paralysis mode upon analysing few deals.While I do like the passive income aspect of a multifamily, I am feeling it's more than second job as it consumes me so much more emotionally and taking me away from my family and I sometimes start feeling if I introduced a new problem to solve an existing problem with this multi-family investment.I am generally a warmly friendly person but ever since I bought my first multi-family and started renting I feel like I have turned somewhat cold. 

Great as I'm not overleveraged at all, but I consume a lot of capital. 

After months of reading this blog and several bigger pocket books I have paid all my consumer debt off and am currently house hacking a row home in Baltimore with my fiance and a roommate.

After 16 years as a sales Agent I had considered opening my own Brokerage @Brandon Carlson, however, after weighing the expected cost, effort, risks and headaches as mentioned by @Russell Brazil, I opted to go with a Brokerage that handles all that for me while I can build & manage my team, have the option of keeping my own team brand, and receive the financial benefits of commissions from the sales of other agents which is generally only available to Broker-owners.