Anything over a 5% return (roughly, I realize more math is involved here) on your new investment would net you positive investment income.  

Their program has about 50% that you read, and the other 50% is an animated man/women explaining things, which helped with certain sections, especially the math.  

Always do the math analysis and try to look at all properties if you have the time to look at prospective properties before you make an offer or at least have a clause in the sales contract that allows you the time (about 10 days) to make a detailed inspection on the prospective property and possibly get out of the deal without a penalty that will hurt you too much.Do not try to do everything yourself.  

Finally, make the math hard on yourself and shop for cash flow only, and ignore appreciation.

It's simple math.

Are there some math formulas that help?

The math would be $15K but I am finding it hard to believe that this is accurate.

Be happy with the niche you select and know the market well too, especially the best locations.Always remember to do a math analysis and try to look at all prospective properties before you make an offer or at least have a clause in the sales contract that gives you some time (about 10 days) to make a detailed inspection and possibly back out of the deal without much of a penalty that will hurt you too much.  

It's all about opportunity cost, and the math is very simple:100% is always better than 50% (go it alone if you can)But 50% is always better that 0% (bring in a partner if/when you must)

@Chris Mason Respectfully, not everything is math...there are all sorts of reasons that someone may be in a position to pay a higher rate, these "challenges" (DTI, Credit Score, BK, F, etc) can be overcome by going to person lender who can overlook these and a deal can be "handcrafted", secured against the collateral vs. fitting into some bank's guidelines.