@Julia Taylor, One of your big calculations needs to be a comparison of moving into a passive opportunity you can 1031 into and keeping the compounding effect working for you. 

Therefore, 50% down does not really fit the narrative as you can just put that into the S&P 500 at a historically 9.75% interest rate compounded over 15 years and come out ahead.

He does have an endorsed local provider (ELP) program for financial advisers and there is a fee for that so it would be fair to say that he gets paid to promote financial advisers who in turn may promote specific funds.Also, I have heard Del state part of the fallacy of Dave's approach is that he relies on compound interest but you can't get more that 3% (or so) from a bank savings account (something like that). 

In order to build wealth and make money work hard for me,I am thinking about how to use the equity I build.After I purchase the property,if the refinance LTV ratio is 70%,the value of property should increase about 40% to refinance all the capital invested in the property.And if the property appreciation compound annual 10%,it need take more than 3 years to get 40% increase.If the property does not appreciate a lot,the refinance does not worth it at all.So I need to use the capital I invested in the property more than once,I need to choose the property which has al lot of property appreciation.Anything wrong about my math?

One of my favorite real estate books when I first started was " the Wholesailing bible" and one of my favorite non real estate books is "the compound effect" both are definitely worth a read.

I was able to teach them everything from using a compound miter saw, to proper safety gear, to applying hands on knowledge when negotiating with subs. 

Your looking at a blended cost of capital around 24%.When I run my hedge fund, we get a blended cost of capital of less than 5% using a credit facility/warehouse line based on Libor at 3.25% currently blended with the targe returns of the fund at 8% (10% to 11% if interest is compounded).

There are many other great mindset books out there like Richest Man in Babylon, The Compound Effect, and etc.However remember, mindset is useless without application.

The secret, is you must also understand exactly how money works, and the importance of how compounding works.There are three Modules you must design in your REI to take advantage of this type of funding.  

I am thinking that i should be able to take advantage of both in the form of ROTH and using after tax dollars and thereby allowing me to take advantage of compounding effect of tax free growth.