I have my sights set on the market I want to invest in and I have a realtor sending me deals, but the realtors are wanting a pre-approval letter with the submission of the offer.

That's why I'm telling you not to focus on them too much, they might make you greedy and short sighted. 

Just that the extra 235 could be going to principle instead of PMI.  

I took Brian Page's BNB formula and I felt it taught me very key principles, shortcuts, great tips, etc.Thank you!

Principle portion - return of capital, no taxInterest portion - taxed as regular incomePayoff - depends on length held (ie. over a year) and what type of entity it's held in, if you're an "active" real estate investor or a "real estate professional".  

Is that the equity you gain each month paying down principle?

They are both on this sight too.

Having the right to buy a property makes me a principle in the transaction.

I have mainly had my sights of four-plex ranging from $250k to $350k, due to my recent purchase, as well as my immediate, pay yourself first, action always beats inaction, head-first bravado started my first LLC, obtained survives through 1800Accountant and went towards applying for business lines of credit cards, (previously believed I was going to finance completely with cash advances from business credit cards and have not been able to secure enough needed.)

Obviously there is alot more to your situation here but the principle is the same.