But right now, I am building my portfolio in a market I understand and am able to justify the risks that I take because I know the market. 

I'm sure they won't hesitate to use that against me by justifying an increase in the interest rate.

The deal has been on market for a very long time and we're looking to pay them on terms over the next few years, but I want to be able to justify why seller financing is advantageous.

I cannot give you a dollar amount, but you will know when the money justifies loosening up the wallet.You do have to be aware of opportunities missed, but until you have your foot in the door and build up a little momentum you have no reason to network. 

Lastly, I am planning on living in the vacant downstairs units while STR'ing it on the weekends as I'm out of town Friday - Sunday so that helps ease some of the negative cash flow off the start as it is essentially my 'rent', at least that's how I'm justifying it for now.My knees are currently shaking as we get to signing as the biggest 'fix' I have to do with the property is raise the rents. 

My strategy has always left cash in the deal, but I can't justify leaving 100% in a property.

Class C locations tend to be full of properties that owners spend as little money on as possible because the max ARV and rent amount doesn't justify making improvements. 

Sometimes you have to justify the purchase and why you’re moving.

It is easy to justify if you use contractor labor charts that you may be able to get from your insurer. 

That said, this still would not justify a negative cash flow position to me.