With potentially less marketability you may have to sell at a higher cap rate in order to unload the property in the future if that is a consideration.The other consideration pertaining to liquidity is the fact that some banks simply will not finance or offer much more restrictive programs for buildings with that type of unit mix so I would talk with local, regional, and national banks to see if they have an appetite for that type of collateral.

That being said, there are over 20 other municipalities in Pinellas County besides St Petersburg, and every city has it's own laws, rules, restrictions, and enforcement appetite/resources.Here is an interesting article that covers many of the issues:http://www.tampabay.com/news/localgovernment/pinel...

Start a discussion with the owner and gauge his appetite for wanting to sell and see if he has a price in mind.I am currently buying two properties from an owner referred to me through my property manager, at the moment we don't have a formal contract just a hand shake deal, since I told him I needed some time to wrap up a few other things first.  

I'd suggest driving around to get an appetite for the area: it's definitely a street-by-street sort of thing.As I've said elsewhere, I feel like the market here has heated up quite a bit in the last ~3 months, so it's been hard for us to find good deals, but maybe things will calm down in the winter.

@Dan Zhang  100 year old property will fall outside the appetite of most insurance carriers.  

Your market's appetite will ultimately determine what is fair....trust the numbers.Good luck!

I wasn't diversified at all and just wasted time managing 3 clone accounts  with the same underwriting and loan appetite.

Personally, I won't buy property with such suppressed rents (unless I can significantly improve them). 

You can find out which banks have an appetite for parks by asking the MH/RV brokers in your area. 

Whether it makes sense to invest depends on your hold period and risk appetite, would love to get a better sense of what you’re thinking.