Millionaire RE Investor - Discount you Require

[Lee G.]

After reading the Millionaire Real Estate Investor by Gary Keller, the one concept which I had not previously considered is "the discount you require" as one of the key factors in your buying criteria.   

I would appreciate other opinions on this concept of how to come up with a viable strategy applying the discount rate you require when making offers.  I'm not sure how realistic it is to say you expect a 20% discount.  However, in my mind, if you could achieve a 20% discount on every buy, it would almost be guaranteed success.  

My current approach to buying multi-families is that I run my numbers and once I am satisfied with the ROI/cash on cash metrics and that becomes my purchase price target. Should I be taking that calculation and reducing it by a discount rate??