Deal analysis, am I on the write path with this one?

[John Stockinger]

I'm trying get better / faster at some back of the envelope type math to determine if a deal might be worth looking into. I've put together a simple spreadsheet where I just plug in some basic numbers and spit out an answer. 

This is my latest deal, a trailer park 

• 10 spots, 9 are occupied. 
• I've put maintenance and management at 5% because their P&L (3 year history) includes those in their operating expenses
• This is 20% down, 6% interest, over 30 years
• There's an opportunity for another $500 in rent by filling up the last spot

Questions I still need information on

• How many, if any, of the homes are owned by the park
• Is owner financing a possibility

Am I at least on the right path? Any suggestions? My initial thought is yes, this property is worth looking at.