I'm not arguing the majority of people who live in C and D neighborhoods don't care about credit.

My property only appreciated $200k in the 15 years so the agent argues it's better to change neighborhoods to expect 3% appreciation per year. 

I know all the arguments why this doesn't negatively effect, or some even tried arguing it benefits clients (including fiduciary duty, future referrals, etc).

I would argue most people would rather have a washer/dryer.The sloped ceiling is less important for a secondary bathroom.

I would argue that someone investing in California are much more likely to invest in a low class neighborhood than someone investing out-of-state simply due to prices.

The best resource I can think of for commercial multifamily investments is:  The ABCs of Real Estate Investing by Ken McElroy.As far as other commercial investments go, I think large metros will have fruitful REIA meeting with people who are highly successful in non-residential commercial investing.Good luck, Kartik!

I guess taking that into consideration you couldn’t even argue in court that it wasn’t a toxic mold because there’s no proof.

Do I have a leg to stand on in arguing the bill should be forward on to the previous owner?

I would argue it's the latter.Let me explain.The average single-family rents for $1,000 a month and I charge a 10% fee ($100) per home. 100 homes would earn me $10,000 a month income.An investor like David Greene walks in the door and asks me to manage 100 homes at a discounted rate of 7%. 100 homes would earn me $7,000 a month income.In both cases, my workload is the same.

Though many can argue that the intangible value can be converted into monetary outcome, I just don't see that as the case here.