- property management fee (someone has to manage this property, even if your self managing you need to pay yourself for your time) I would use 8% for a property management fee ( there is a whole litiany if charges such as placement fees etc that get charged as well but to keep things simple let’s use 8%) keep in mind your area might be unique i would call some local PM’s to get a feel for the cost.

Very specific situation I've got here that I haven't been able to find good information online that fits this unique criteria.I have a friend that has a property that they own free and clear of mortgage, yet they are paying a HELOC of approx. $300 a month for.

I have plenty of friends with much nicer cars than I have, nicer clothes, better toys, but my sacrificing those things gave me something that they don't have; freedom. 

We actually toyed with the idea of renting year round once we knew we'd spend a few months down there so that we had a place to run off too any time.

Move to less expensive housing, cancel all your electronic toys, spend less time and money with friends etc.If you make saving and investing your priority in life you will be amazed at how much money you are actually wasting on useless items every month.  

This is really unique situation, the residential properties near by has different use, therefore not good for comparables. or do I let them do their market research any way?

I think a broker is a good option, particularly for a unique or challenging circumstance such as the one described above.

what I find very unique right now Ned is the amount of HML or private money companies led by large hedgefunds investing in these HML companies have driven these private rates down to 10% apr or less.. so to only have about a 4% spread between bank money and HML is quite unique in my experience over the decades.. other than the high interest mid 80s anomaly.. 

That being said, real estate does offer some unique tax planning options.

Recession resistant asset class (people downsize, move in together, move back home, etc. during recessions)Cash flowing asset (not dependent on market appreciation)People buy a lot of crap and toys during good economic times (and need a place to put it)75% of the facilities in the country are owned by non-institutional owners (opportunity for adding value)Small ($10-30) rental increases create large increases in NOI and property valuationSticky tenant baseUnits are easy to maintain (brick and metal, no amenities, little landscaping)Location, population growth, and barriers to entry matter.