running comps + mixing SFR & small multifam. units

[Jeffrey Grieshop]

I was looking for an answer to my question but I did not have a lot of success. 

When running comps, can I equate or compare a small multifamily unit (2-4) to that of an SFR? If my criteria match for the comps, can I interchangeably compare these two? Or are there further considerations? I am mostly asking about SFR's that have been turned into a multiunit. For instance, there are many standard looking SFR's that have been converted to 2-4 units, right? So, let's say we have two identical properties but one has been divided into 3 units. Other than that, they are literally the same, even the location. I am now trying to determine how these would differ if I was going to buy them. Naturally, I would think the triplex would be the better buy, by far, at the same price, because we could rent it out to three people instead of one. So, I am trying to extract even more information and things I should think about in this scenario.

If that same triplex mentioned above sold 3 months ago for $100k and suddenly the "exact same undivided SFR property " is listed on the MLS, do I assume its value is $100k? Again, same property, same location, hypothetically speaking(except this one is a SFR not divided into 3 units).