It's a huge gamble because I've seen properties go for 50% of FMV and others go for more than 100%, it all depends on who is bidding and how desirable the property is. 

Please excuse my desire for facts rather than conjecture such as that which you posted.

I usually get a feel for or discuss the owner's desires and tolerance for rent increases along with my opinions of the market at the time. 

It doesn't have to be degree, but a mentor who has a investment portfolio you desire.

It is quite probable that areas in different parts of the City may see properties selling at different CAP rates based upon desirability and risk.You also must remember that CAP is a course indicator of valuation - you would still need to examine the particular deal and make adjustments for age of the property, state of repair and current performance.

@Sal DeMarco  being desperate and being full of desire are two different things.you can leverage into and get good deals on MHP that are full of Junkers and tenant base is basically pretty rough... you get those from burnt out landlords.. or elderly people that finally give up after owning them for years and they let the park get to a state that it is not financeable.

You're on the right track with desiring to get the education before jumping in.

Long before finding BP, a friend of mine called the out of state owner to inquire about his desire to sell. 

I have a spreadsheet that uses the same formula but rearranged to determine my max purchase price for a desired profit.

If it is desirable and fair to you, take it.