Wondering if you have advice on me just being the bank, where I purchase a house and structure a rent to own with him and have him build up a 30% cash down payment and some equity and then me sell the house to him at a locked in price.  

Down PaymentSaving for your down payment is likely top of mind.

True re the prior poster, re this helping the seller save their credit, if you buy sub-to you will dramatically raise their FICO since the mortgage will show on-time payments.  

Any other expenses are using up funds that would otherwise be sitting in your checking account to make a mortgage payment with.

.I took the average $4,000,000 house in Pacific Palisades CA and it shows a monthly tax payment of $4,167 for a total of $50,004 a year.

These methods include: Detailed Engineering Cost ApproachDetailed Engineering Cost Estimate ApproachSurvey or Letter ApproachResidual Estimation ApproachSampling or Modeling ApproachExperience or “Rule of Thumb” ApproachIt’s important to understand the differences between the approaches including which one best fits your property and the reliability of each approach.DETAILED ENGINEERING COST APPROACHThis approach compiles the costs from construction and accounting reports to build a report.

@Jaycee Greene I wouldn't have the funds for the down payment. 

@Jason Malabute Yep - I'm currently invested with BAM in Fund #1 and Fund #3 (no money in the war-chest when #2 came around)Distributions have been consistent and reliable and Fund #1 has already generated a 2x equity multiple.

I was thinking he supplies the down payment and acts as a silent partner.

Wealth-drivers are appreciation, debt pay-down (ie. principal payments) and tax shielding.