As an investor, you always want to make your money stretch as far as it can, and multiply as much as possible.

We then apply a multiplier, which depends on the industry, competitive profile, length of time in business and several other factors. 

You can can multiply model and create community.

Take the monthly difference multiply out by number of months to determine ROI.  

I was told by a GC out of NC that to estimate cost of repairs in a property you would consider a light rehab you could get the sqft of a property and multiply by $25, medium $35, heavy $55 and full rehab $75+.

If you experience the same appreciation rate as my initial property that $1.9K increase would be multiplied by 4.9

Now you might be only to get 1 property buying with all cash....so LEVERAGING your cash will allow you to multiply your long term strategy which is why we all use loans anyway...even if we have the cash to buy outright.Hope all of that makes sense but feel free to ask anything additional.  

I think I have a solid foundation but I am interested to know: Is there a certain multiplier I can use to convert median price of a single family home into the approximate value of a multi-family home?

Multiply that by .75.

You are better off getting the value based on the current rents and determining your ARV based on the future rents using the Gross Rent Multiplier.