. $10k for a roof (at least here in my area) would be pretty low for most triplexes unless its a small area and no gables/valleys et) A new sewer line to the street often based on total length.

Those use a AVM based off Zillow or electronic records on file.

Within the nonQM space there are products like DSCR, bank statement loans, P&L loans, asset based loans, etc.

I would recommend first establishing what your financing options are based on your cash on hand and cashflow expectations....  5% down? 

The ability to make a cash offer and the absence of steps required to obtain hard money makes it easier.

The 5 year proforma by DEFINITION is based on a whole slew of assumptions about a whole host of issues in the future - national economy, local economy, interest rates, cap rates, rental rates, political and geo-political factors.

Closing costs vary based on State and County for Taxes, Insurance, Doc stamps, transfer taxes, Title, and every Bank/Lender requires different points/hard costs.If you have any specific questions of if your just getting started feel free to message me or reach I out. 

I'll be moving to McGuire AFB in New Jersey and am looking for my first property within an hour of the base.

The ability to get into multifamily and bring in some more cash flow via a medium term rental has made the interest rate environment less relevant.

Sounds like it's been vacant for a while based on your narrative.