I did not mention, but this is a probate sale, and the seller is the executor of the estate.

What should I pay attention to if i was to get a property in this situation through an auction?

So many things wrong with all this.First don't pay for this.

Duplexes for sale starting at $585,000 with a 3.75% interest rate.

Purchase price: $341,000 Cash invested: $136,000 Sale price: $519,000 A house that I bought, renovated, and sold.

I have the credit, experience and the knowledge on how to underwrite the deal to show their ROI in this arrangement vs a traditional sale. 

The reason is the rent-to-price ratio is good so you can cash flow, and most of the West side doesn’t have a Point of sale inspection which is really annoying.

You are bold for taking on a non-paying tenant. 

Imagine you make $100k and you are affected by 3 tax brackets.0-33k =-33K 0%33,001-66k 10%66,001 - 100k 20%You can take $100k in deductions this year and pay zero taxes, for one year and then $10,100 for for 2 years  ($20,200 total)You can take 67k in deductions this year and pay zero taxes for a year, take 33k the second year and pay $6,800 year two and $10,100 year 3. ($16,900 total)You can take 33k each year and pay $3,300 in taxes all 3 years. ($9,900 total)Obviously this is simplified but unless you expect to make much less and be in a lower tax bracket in the future those deductions could come in handy.

All rents you get from this property has to go back into the SDIRA but if you get a 20 year mortgage (that the rent can cover) and can pay the rental off by age 65 you will have turned that $90K into several hundred thousand’s of paid off real estate.