I asked if there was anything else we could try, he got very angry and demanded I pay him in full.

Imagine making millions of dollars over the course of your career and then having to pay 30-50% every year to uncle sam instead of compounding that cash over time.This is exactly what real estate professionals have learned to mitigate.To reduce their taxable income, they just buy a building every year, do a cost seg, and use depreciation to reduce their tax liability dramatically.Their personal wealth snowball grows much larger and much faster than their W2 counterparts who give most of their money back to the government each year.Following this strategy as a real estate professional is one of best ways to end up with a much larger net worth at the end of your career.

Somebody somewhere had to pay for that real estate at some point and has continued to pay for it since.

Things they did bad which I wish I had asked more information about:Never involved in the screening of tenantsThey recommended keys for cash by waiving the rent amount buy only collecting fees which they would get not meThe cost to evict is 750-950 yet other companies told me they will include eviction in the priceThe tenant didnt pay in full last month and I was the one calling out to them and asking questions then a few days later I get an email saying something happened with the tenant and they are investigating.You get passed from person to person every week or so.No one told me when the construction was complete and so the house was ready for a week and the post to zillow and other sites was not done.It took them another week to take pictures and then another week to upload it.I was paying 200 dollar a month electric bills while the house was vacant because they left the AC running in the empty property.

But I would not consider what the seller needs to make in determining what I'm willing to pay for a property, especially when youre buying a problem like this.

After fully renovating both units, I refinanced to pay off the loan and held it as a long-term rental.

The hang up is getting deals formally drawn up.One idea:- I buy the property and pay 25% DP, then they provide capital after the closing and I pay them P&I over 5-10 years.

Who pays when the resident breaks the agreement and quits paying? 

You will be paying 6-10% for just having them collect rent. 

Determine at what percentage of completion you'll pay for work done. i.e.