I have reduced the rent by $200 a month as a winter-teaser rate till July, and will see how this goes:-) Sorry for not being able to thank each one of you individually -- I really appreciate you taking the time to help out a (frustrated) small investor! 

Supply/demand: your supply of "one 55+ duplex" isn't going to change, but the number of 55+ people 'demanding' to live in it might drop off, drastically reducing rents and/or resale value.

Also I didn't see anyone mention this, I may have overlooked it; but if the asking price/sale price doesn't work for you reduce your offer until it does make sense and the make an offer based on your number.

Id go with @Adam Schneider on this one, check online on public record to see if its paid off and offer full ask with your term financing.

If on the outside it looks like there's a shipping container in the back yard with a couple window cutouts, that might not make the neighbors happy, and might reduce the value of the main house.  

I'm just looking for anyone who has been successful going back to the seller (especially if the seller is the bank) and getting remediation in the form of a reduced price.

Have you reduced the price?

But there is to much consequences now that you have publicly posted it online.

In fact, it will increase your taxes by lowering your interest deductions as you pay down principal and reduce interest charges.

Just be mindful that the seller does not want the information about their particular offer/sale made public.