From google maps pictures (2015) there were 5 additional homes that have been moved or torn down.EXPENSESStick built homes pay for all utilities.Park owner pays for water/sewer of mobile homes.Property taxes $2,000 yearly (166.67/mo.)Water/sewer, Trash, landscape, snow removal, etc monthly average $350There are additional misc expenses roughly $40/mo.Asking price $65k (15 yr mortgage about $400/mo.)Insurance unsure yet.  

Am I miss some additional costs?

However isn't the additional $16,920 I paid can be counted as expense when I purchase the property?

Thinking what is the catch, a good way to diversify and minimize risk over owning individual units?

Additionally, because we bought in a popular owner-occupied area, we've seen the property's value appreciate over %9 in the past 3 years.Food for thought.

Based on this report, I have asked the seller for an additional $10K at closing to make up for some of the costs I'll be incurring from the start.

You can probably add it to your existing cell phone plan for $40/mo or so.

Hopefully you'll find that additionally helpful!

At the price point of our properties, it ends up being a little over the 6 months of mortgage payments per property that the commercial lenders in my area like to see prior to lending on additional properties. 

Imagine being an auction company and offering damages to buyers when a seller can't close because they didn't calculate properly or foresee additional lien payoffs.