Turning a historic duplex into a high-performing asset while forcing $100k in appreciation is no small feat—seriously impressive. 

@Denise Lang Starting your real estate investing journey out of state can be strategic given California's high costs and tenant-friendly laws.

If you offer more $ for the property than the all cash offers AND you appear to the seller to be highly qualified in the method you are using for sourcing the payment, at some point your offer will be more appealing than the all cash offers.I don't understand why you would consider a 1031 for another property in two years. 

With a 4-unit building, that’s a very high customer concentration.

If you go into A/B Class the rents are going to be too high to justify doing section 8, meaning market rents are higher than Section 8 is able to pay.If you go down to D Class areas you're going to attract terrible tenants and it will be a nightmare. 

But, I don’t think that should be a very high bar for you especially if you are already studying and researching this at 18 years old and you don’t plan to buy anything until 2-3 years from now at the earliest.

TLDR: I don't see a reason for small landlords to use concessions - either the price is too high or you need a remodel if your unit isn't renting.

Since you're analytic savvy, run some high level amortization schedule scenarios to see how much equity you gain through annual principal payments.

It's highly unlikely to go that low again in your lifetime.

Based on your numbers, and assuming you have a credit score high enough and have never filed for BK, you shouldn't have an issue getting approved for an HML to buy/rehab the property that I would estimate at about $370k-$375k (which includes 100% of the rehab costs).