I would also add in some number for "reserves" on a monthly basis for each unit, perhaps $100-$150 per unit per month to start; you want to make sure you have some funds available in case you need to replace a roof, hot water heater, etc...

Congrats @Joshua HughesI have had a ton of luck with apartments.com (they bought Cozy).

So, our regular plumber mentioned that the price of water heaters looks like it's going up significantly. 

Unless the property is under water, that seems expensive.

From my research the fees go towards hot air heat (from what I read about the property is the association pays for oil), water, snow, trash and grounds maintenance. 

@Mike Gonzalez keep it simple, its gross rent less taxes , Ins, PM ( property management, 8% of gross rent ) 5% for misl, and any other expenses, snow, lawn , water etc, divided buy your PP.

After Mortgage ($2610), Taxes ($1114), Insurance ($250), Water/Sewer/Trash ($400), Landscaping ($100), Security ($150), Repairs & Maintenance ($350), Reserves ($625) and 5% Vacancy Loss ($600), the Total Monthly Cash Flow is $6286.

You'll need to pump it out, get in there and tear up the bottom so water can drain out.

Here is an example of a house built inland that took four inches of water in Sally… it was mine.

Roofs, floors, appliances, hot water heaters, hvac, exterior siding or paint, etc.