Finally the CAP does not tell you anything about the quality of a cash-flow, just its cost relative to its peers.So if you had a 100-unit property in Manhattan with a CAP of 5% in might be delightful, but one in Toledo with a CAP of 5% probably is not .... furthermore, using CAP to compare these two properties is dangerously meaningless. 

I've not really thought about that (aside from just having a bit of savings for unexpected emergencies).

I do this to be sure it's still a good deal even if the HOA dues go up unexpectedly.

If they do not, they aren't going to be great investors when there is an unexpected expense, problem etc.  

That 30% spread covers your butt generally for the following expenses: realtor/advertising fees (4%-8%), conservative PITI holding costs (4%-8% for 4-8 months to fix and sell), closing/fianance costs to buy (1%-6%), closing costs to sell (2%-3%), and unexpected expenses/repairs (1%-3%).

However, they know that if they do it often enough, to enough people some of them will arrive in a prospects hands at the time that they're contemplating selling the house, or (in the case of insurance guys) on the day they found out that a friend died unexpectedly, which causes them to call the person who mailed.Ask yourself how many cards and letters you'll have to mail to hit those few folks.all cash

Taking into consideration any repairs, maintenance, and unexpected vacancies, what would I need to be netting from rentals each month in order for the deal to be worth it?

One of the great benifits of the NNN lease property is that you are not caught off guard by things like property tax increases, lots of snow removal, unexpected repairs, and things like that because most (if not all) expenses are passed along to the tenant.

One unexpected move out and you're paying the mortgage.Where as with an apartment, you have economics of scale working in your favor.

Can your reserves handle an unexpected $150k expense?