The vast majority of the applicants I accept are well above that score.Credit score is a measurement of financial responsibility and is a very important metric for assessing any applicant.

Obviously I'm a real estate investor/broker/developer and so I also tend to be optimistically conservative in my assessment of real estate markets and opportunities in spite of my memory of 2008 (which feels all too familiar at the moment.)

My sweet spot is vacation rentals and assessing highest and best performance in various markets, looking at NOI vs CAP, evaluating acquisition, expenses, exit strategy, and modelling for various scenarios with a near infinite number of levers we can tweak to account for any nuance in any variable. 

Without all the extra details, it's assessed at $135,000 but the owner says to make an offer, that we have them where we want them and the sooner the deal, the lower they will be willing to go.

We are able to assess this with a real estate agent prior to purchase  and look at tenant ledgers to ensure cashflow upon purchase. 

Look up the address on the city's database: https://www.cityofboston.gov/assessing/search/If you PM me I'm happy to help you do a little digging.Some red flags are: (1) odd basement units, (2) units without proper egress, and (3) units that were broken up several years ago without permits to try to limit the number of unrelated people living in one dwelling after new rules were put into effect.

Wish I had a comprehensive answer. 

Do you agree with the rest of the assessment, that otherwise your are vulnerable?

Small cities can be vulnerable too, and it is often difficult to assess the health of a dominant employer.

If you are going to borrow funds to acquire notes, you'll need most of your cash on hand as reserves to carry the obligations you have vs. the income created from the notes (principal, interest, late fees and other assessments, if any).