@David Ribardo and @Joe C jump in with any edits/comments you might have Purchase Price $149,900 (50K a door rule looks good) Three units total gross/month 2239 (1% rule looks good) Fixed expenses: Taxes 2517, Trash 1125 (375/unit in Allentown unless private collection deal previously arranged) Insurance: 703 Common Electric: 519Water/Sewer: 802Allentown Fee: 225 (75/unit/year) Variable Expenses:  Vacancy: 2239 (One months rent of each place, or 8.3%) Management: 1800 (50/door/month) CapEx/Maintenance: 3000 (1000/door) Total Operating Expenses: $12,930 Total Gross Income: $26,868Net Operating Income: Op Ex - Gross = $13,938 Divide your NOI by the cap rate your looking for and you have your offer price.

There are a few variables that go into which structure you go with, so you would want to talk to local attorney and CPA that knows South Carolina's state tax laws. 

Sorry if this is a rookie question and I understand there are a million variables but if someone could share their expertise based on experience it would greatly help the design of my strategy.

Honestly, check the sources of the economic variables you indicated.How many cranes can you see downtown?

The second major variable is the cost of building.

I realize this is a very open-ended question since there are lots of variables, but I'd appreciate any thoughts on what would it cost to build a single family house in Bellevue/Issaquah area.

You're likely in a much better position going with a Variable & 30 yr AM.

Be aware that the interest rate on that LOC is variable (typically adjusting each quarter), so have a plan (back up funds) to pay it off quickly if the rates go up too high too fast for your business model.

Like all insurance it is highly variable.

Of course, since the payback is variable, perhaps the investor holds a tax consequence, even if I pay the capital gain / ordinary income tax.Has anyone experienced that?