Our idea is to continue living in our unit and have our next-door neighbor (attached unit) pay us rent, which would help cover our new mortgage.

Do you pay them? 

I would expect to pay under $20,000 for a three-unit property.

Hi folks.

One of my properties cost me a little more, but the other two were less than what I was paying with foremost insurance.

In Worcester, I think your numbers are pretty close, but there are also a lot of Programs between Mass Save, and the City of Worcester that will pay for many of these things if you agree to an income restriction, or sell income restricted. 

I have about $15k I have to pay back for school.

You're just using new debt to pay off old debt (which is the same concept as your alternative: refinancing your primary to pay off the HELOC).

Patience does pay out.

Then reinvest all the profits for myself and the money lender until we reach a future goal ($600K).The question is, if the money stays within the LLC then I assume that I am paying roughly 20% corporate tax on all profits from each project.