I'm contemplating spending up to $15,000 to buy into an established mentor/coaching wholesaling program that focuses heavily on the marketing and system components.   

Cash flow is a big component of the puzzle, but it should not be the only factor considered. 

Rather you should go with a component valuation.

They can still do ports but with restrictions, and then they'll give you a blended rate, and the 2 mortgage components don't ever come due at the same time, and it's messy.

@Tobey Porter vacation rental management is definitely more hands on than regular residential and there is a huge marketing component that is crucial to keeping your property's vacancy as low as possible.

If I'm understanding you correctly, each income component is classified into it's own bucket and taxed as such.

Appreciation is a core component of most investment returns in real estate.  

Research the different ways to invest in real estate find the one that interest you so you enjoy learning about it and consume as much as possible on that aspect; whether its single family house, small multi-family, apartments, commercial, buy and hold, fix and hold, fix and flip, local investments, out of state investments, self-managed, professionally managed etc. as soon as you have an understanding of all the major components of that type of investing start looking for a relatively low risk deal to break yourself in on to gain experience, but don't stop reading up and learning more and more about your chosen area.

Its not well presented in the class component.

You can then develop a more accurate CapEx reserves requirement based on the estimated usable life expectancy of major components/appliances.Hope this helps