On property number one, I would cash flow $750 a month after mortgage, taxes, and insurance if I also rent out the unit I live in.

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.

Wanted to still be close to family but maintain a cheaper lifestyle, still have strong appreciation, and much better tenant/landlord laws, taxes, etc. 

Start by talking to a cross-border CPA and attorney to handle taxes and legal structures properly.

You'll likely want to evaluate the investment with UDFI tax figured in.The Solo 401k trust would make the payments to the seller/lender and would also pay for any investment-related expenses.

I've been knocking on doors, there is one that seems like it's abandoned, however despite finding the owners name from tax records I cannot seem to get in contract with them to make an offer (despite trying x, y and z). 

a lot of people will poo poo this, but I also live in a market where cash flow is low, property taxes are high and properties are expensive (which is a relative term).

Thats $7700 a year NOT including my accountant/Tax prep. 

It's almost like they tack on a few hundred dollars to the order and forget to charge sales tax

People claim that 1031 investors over pay all the time just to avoid taxes.