Look up the courses taught by Justin Kivel, specifically the Pro forma modeling course and the real estate financial modeling boot camp.

Even in the nice locations, most top out around $2,800.Of course there is also your increased insurance, vacancy, repairs, CapEx, and the never mentioned reduced rent on the main house since having a stranger living in your backyard usually isn't appealing to most renters. 

I get people calling crying they want to sell their lot they bought for $50,000 and I tell them they're lucky to get resale at $5,000...then of course they don't want to sell....but if they don't sell they're paying $1000 year plus property taxes for a lot that likely won't go up in value for years.So think about your exit strategy. 

I don't ski, so Snowshoe sounds like it may be a good fit!

Of course, you would need to do your own research and due diligence when purchasing a company but perhaps that's a way to get involved in the trades in the owners seat.

We also do a property orientation and show them how to operate the house, change filters and batteries, turn off water main - and of course the mystery of GFCI outlets

Of course the risks are there that the owner will not renew the lease and start doing it themselves if you are successful.

I'd say the logical paradigm in the question is a bit off.CRE includes everything from airports to golf courses to hospitals to campgrounds.So saying "residential versus commercial" is like saying "bacon versus plant life."

Have you personally tried any courses or training concerning land?

Of course the listed price may not be the actual rented price, but by tracking several listings for a while you can gain a better understanding of the market.