Comparing these terms to the best financing I've found through a bank ($320k loan, 5.5% fixed for 10 years then refinance, amortized over 25), with same purchase price and down payment, results in a lower monthly payment by $315/mo, plus my principal balance after 10 years of payments through bank financing would be $240,000, compared to the $180,000 balloon that the seller wants at year 10. 

Sometimes you can just offer lower rent or possibly no down payment.

Re laundry money, i never include this in my calculation - i simply look at it as bonus income. your vacancy at 3% sounds low, again not knowing the location its hard to sell. 5% would be my lower estimate in high demand location and proven 100% occupancy in the last 2-3 years.Repairs and maintenance, unless the property was recently renovated top to bottom or you would renew the large items like roofs, HVAC, water heaters etc 5% and 4$ is tight. 

Comparing these terms to the best financing I've found through a bank ($320k loan, 5.5% fixed for 10 years then refinance, amortized over 25), with same purchase price and down payment, results in a lower monthly payment by $315/mo, plus my principal balance after 10 years of payments through bank financing would be $240,000, compared to the $180,000 balloon that the seller wants at year 10.

Since they export very little steel to the US they could simply lower the price to other markets even lower. 

Might not be a bad idea to balance out your higher risk properties with a few that are much lower risk.

So if the appraiser knows what he is doing and appraises it lower I would make sure your numbers are good.

.), but he is absolutely convinced that there's no way I could buy lower end homes in my city to rent without ending up bankrupt.

Would like to lower the payments a bit of possible.

My properties are in a lower income area and people have to have a place to live. 2 times the rent is often fine assuming they don't have a brand new car with a relative giant payment.