Considering adding an 8 capnduplex to my portfolio

[Steve S.]

this question isn't so much about if this is a good deal or not, but more a question of when and how do you decide de to expand your portfolio. 

I have several rentals all of which are < 50% equity. I'm considering a property in a good, growing area with a good school district. It would yield 8%-10% but at a minimum 8% based on my calculations.

Id say my cash position is 37% of my total outstanding mortgages.

This is a turnkey property.

What would you consider before making this acquisition? I'm trying to determine if:

1) I'm better served continuing to build my cash or stock positions relative to my outstanding mortgages

2) for only 8% and the hassle of having a rental, is it better to plow the $40,000 down payment into stocks instead (no one can answer this of course)

3) for 8% no rental is really worth it

How do you decide to expand your rental empire or not?