Okay, my level of expertise with the King County Parcel Viewer and Property Report led me astray last night. I didn't believe that the Medhame Alem property was only 4800 square feet but I couldn't verify that hunch. I have since realized that there are three adjacent parcels and obtained the area of each, for a grand total of 15,360 sq. ft. At the L3 max zoning density of 12 units/9600 sq ft., that would yield a maximum of 19 units on the property.
However, L3 zoning requires that only 50% of the area can be covered. According to my numbers, that means seventeen three-bedroom units could potentially be built (and still receive the maximum point bonus from LEED) if the area was spread over all three stories (430 sq ft. footprint). That seems like it would be unorthodox architecture but when you look at the (rough) dollar figures, it is appealing.
If we are still assuming that the property would sell for $1.8 million, that gets us down to around $106,000 per unit, just for the property which is, in my book, much more plausible. Of course the programming could be rearranged for some two-bedroom units and larger footprints could be acommodated; the number would fluctuate, but at least it's within the realm of reality. After reading through the NAHC's website, it seems that the purchase of the land is one of the biggest hurdles and most important first steps.
I apolgize for my previous error and pessimism. I have two deadlines next Friday at work and my brain has been fried.