@Alex FreeloveI don't think @Duc Ong is giving you tax advice, the ratio (ROE) that he mentions has to do with how efficiently you are using your equity (tax implications aside).

Imagine you were on a boat with a friend in the lake and it overturned.

That's a Return on Equity (ROE) of ~2%, which stinks.

@Michael , Let me give you one of the angles you should look at: i'd suggest looking at your return on equity (ROE).

(Because you are increasing your investment size.)Another concept is that of Return-On-Equity (ROE). 

@Charles PhanumphaiI bought a number of foreclosure/ROE properties during that time.  

That means your current ROE is pretty bad and it won't cash flow if you put 75% debt on it.How much total appreciation have you seen (including depreciation recapture)? 

Specifically I'm trying to analyze ROI (or cost of capital) vs ROE.  

Rents don't keep up with values, you don't hit the 1% rule and you either don't cash flow or the Return on Equity (ROE) is terrible.When you say "paper investing" are you referring to stocks and bonds or are you buying notes?

Depending on the rental rates, you would want to calculate ROE (return on equity) and you could potentially see what rents you are getting and refinance some equity out to use on other deals which would increase your ROE, technically lower your ROI on this property but would raise your overall ROI if used on another cash flowing property.