It's what he does.The advantage I saw with my 3 commercial loans (on commercial property)  was I couldn't stand reporting my financials to them every year to such a high degree that I paid them off or refinanced them with fixed rate private money from a hands-off acquaintance. 

I graduated with my degree in Aug 2008, and was working full time as a real estate agent.

I was thinking maybe I'd just take online classes to finish up my degree while I work full time as a truck driver.

You have thousands of people doing the same thing including major operations that have a substantial  degree of resources on the ground canvasing, door knocking, advertising, and submitting contracts almost around the clock.

Househack and get that degree

After getting my degree, I worked for a manufacturing company that moved me out to Harrisburg, PA for a year and then to Cedar Rapids/Iowa City, IA for 4 years after that. 

I have a business degree (supply chain management and marketing) and have been self-educating on real estate topics, but I'm about ready to get my hands dirty. 

My college degree was in business and emphasized real estate. 

Going by the 20 degree rule it's working just fine.

In 1980 I graduated college with honors with a business degree that emphasized real estate.The first thing I would say about your questions is to not depend on any book on construction costs.