Management pad 30% (180)Taxes 100Insurance / sewer 60Assuming no other utilities... 260Finished per unit cost 30k10% cap

In fact, I had a park under contract to purchase and it had 13 pads and was under contract for a 25 cap. 

There's an 8-pad lot right next door.The location is a rural-ish suburb of Kansas City with good schools.No expenses other than lawn mowing ($400/yr).

Nice padding for the GPA too.

@Alex LocklearThe taxes will go up once you improve the land (add septic, well, drive way, electrical, pour a pad...ect).

You can also get a general idea for rental rates by looking at actives on craigslist and hot pads 

Here’s a list, which provides a good start:-Developed vs Raw land (meaning infrastructure, lot/pad delineation, utilities in place, etc)-# of filled lots?

All of this eye wash really isn't necessary, your business plan starting off can be three paragraphs with a supporting proforma statement to a lender, they are about the only folks you'll need a business plan for, except for your internal operations which can be on scratch pads as to you thoughts of the day. :)

I would love to be making about 500.00 a month in passive income to pad our current income and free us up to pursue some big dreams (like building our own home on our own land.)  

There's currently one down in Chandler for sale with 6 normal units and 4 mobile home pads.