If the cost approach is relied on, it can't be given more than 49% (last I heard) weight in the final analysis.

I'm curious because I'm weighting out buying a multi fam or a single fam house.

And FYI, pre approvals from HML's don't carry a lot of weight with any type of informed seller.

I can tell you from experience wholesales, good ones, are worth their weight in gold.

Investors often get cheap with the wrong things....a good manager is worth their weight in gold or platinum!

There are a multitude of risks although most SHOULD be lessened with proper and extensive due diligence on the property prior to even acquiring it.

That's not to say it wouldn't happen, but that person has all the risk and is allowing you to partner for half the profit.More likely is a split of the capital, and LLC agreement as the instrument, and then some split of the profit that is weighted by risk and responsibility. 

I'm also somewhat more lax about inspections on condos and townhomes - if the HOA is responsible for the roof, structural, sewer, exterior, etc then that lessens your risk as well. 

Am I not putting enough weight to the risks?

How much weight do you give the most recent comp over comps back a couple of months ago.