Do you have enough money left over from your home sale to finance the 4plex as an investment property (additional 10-15% downpayment.) and then still have enough left over for a downpayment on a new home?

Also chat with a commercial lender as most investors eventually outgrow conventional financing at some point. 

If so, you need to make some good guesses on what YOUR NOI will be, what your financing will cost you, and then back into a price.  

These are the top two.One: I'm (voluntarily) unemployed, Don't know how I'll get financing.2) They think they're going to get $75k for it.

I would think rent to own or owner financing would work superbly.  

How did you finance this deal?

There’s a house that need some major renovations that interested me and I was hoping for some insight as to how I should go about financing (once I’ve finished the project that I plan on buying and rehabbing in cash).

Let me know if you have any questions in regards to DSCR financing no income no doc 

Do you know if you have conventional or FHA financing?

I don't have other properties I've flipped or upgraded to give the banks confidence for financing.