Unit empty since March and I keep changing my mind on the rehab

Every week that unit sits is rent you never recover. Eight weeks of construction at 1,050 is 2,100 gone off the top of your return.

Let me make sure I've got this straight. PITI is principal, interest, taxes and insurance, the whole mortgage payment, is that right? And if the two rented units cover the 2,180 plus the 180 in utilities, does that mean the third unit is basically all profit once it's filled, minus repairs and setting money aside for the next vacancy? I ask because everything I read about single family says one empty month wipes out the year, and your building clearly doesn't work that way.

Fill it. You have 9,000 in reserves for a three unit building and you're talking about spending twice that on cabinets. Do the 2,500 version, take 975, get a tenant paying you while you rebuild the reserve, and revisit the full kitchen in two years when the unit turns again. Income you have beats income you modeled. I want the version of this that doesn't turn into a second job, and borrowing against the house to chase 250 a month is the opposite of that.

The math depends almost entirely on which rent number is real, and your own comp range says you don't know yet. Before choosing a scope, get three actual data points on 1-bedrooms with no in-unit laundry rented in the last ninety days, not asking prices. Asking prices in a wide range usually mean the top of the range sat for a while.

On the payback framing, @bramble has the arithmetic right, and there's a second piece. The full rehab also lifts the building's value if you ever refinance, because appraisers on 2-4 unit residential property lean on sales comps rather than income, so the kitchen shows up in condition adjustments rather than as a clean multiple of the rent increase. That's a weaker value transmission than most people expect from small multifamily. Don't underwrite the rehab as if you're buying NOI at a cap rate.

On reserves, 9,000 across three units in one building is thin. One building means one roof, one sewer lateral, one service entrance. Diversified tenants do not mean diversified structure.

The scope I'd price out that you haven't listed is the middle one done in a way that doesn't have to be redone. Cabinets, counter, flooring, paint, keep the existing vanity, skip anything decorative. That's usually well under the full quote and it's the same unit to a tenant at 1,150.

One caveat on financing. If you do end up borrowing, terms and qualification on a HELOC against an investment property differ a lot from an owner-occupied line, and you should get the rate, the draw period and the reset language in writing from the lender before you commit to a scope.

Disagree with @marlow on the used kitchen. I did exactly that on a duplex to save cash and I turned that unit twice in three years because it showed like a compromise. Cheap tenants for cheap finishes, and the turn cost me more than the cabinets I skipped. The middle scope @rena-expert described is where I'd land, priced hard, one trade at a time if you have to. Also get your contractor to commit to a finish date in writing, because eight weeks of quoted work has a way of becoming fourteen.

Watch the rent ceiling. In my market 1-beds top out around 800 no matter what you put in them, and people spend anyway because the kitchen looks good on their phone. You have a 375 spread in your comps which is unusual, so I'd want to know if the 1,325 units are in a different school zone or on the other side of a main road. Cheap markets teach you fast that finishes don't move rent past what the local wages support.