As a CPA and real estate investor who is a general partner in two syndications, I want to share some practical advice to set realistic expectations.

So there is huge risk expecting the 15 year limit to be reality.  

Rent out to roommates so I employ the "rent by the room" essentially.Pros:insane cash flowif your room offer is much better value than other places to live, tenants will stay awhilea small community can be built when your tenants become friends with eachothernever ending supply of tenants (at least in my area)Cons:CAN BE management intensiveWILL BE management intensive until you gain experience and know how to manageIf you employ this strategy, the BIGGEST risk/liability mitigator is being VERY clear from the start about your expectations and that you will evict if new tenant doesn't follow your rules.With my setup - I furnish the rooms and have all utilities covered. 

If a seller doesn't know where they are going, you aren't buying their house.Also, you are probably expecting to get somewhere on the first call.

And how much can I expect to spend on this process?

You have to look at deals for what they are and you have to be real with your expectations.

Not saying that those are possibilities but understanding those potential outcome and doing what you can on the front end (screening + clear expectations) to avoid them.  

If you own a business that you have no understanding of, how in the world do you expect to not lose? 

I don’t know what they expect to find.

A paid off property at 5-6 cap rate should also appreciate at about 3.4% per year on average, so my real estate return at 8.4%-9.4% is reasonably close to what I'd expect in the stock market, and the income is tax advantaged.