One of the biggest mistakes beginners make is relying on an agent that typically sells owner-occupied housing--most of those agents don't know enough about investment property to help you do the proper due diligence necessary to close a good deal.  

@Tim Pagano ACCURACY and PRICE are the two biggest factors in my opinion.

I think the 2 biggest deceptions I see with some turn key companies over the years is 2 fold. 1.

Hey Bill, this is my first mobile home, and it's also my biggest deal so far.

just as @Barclay Hallowell  explained far more complicated than it looks.you may want to start with a simple lot split or a minor partition.. those are less onerous. once you do 4 lots or more in most jurisdictions this is deemed a subdivision and has a much more rigorous set of hurdles to jump over.As well as this is HIGHLY regionalized.. in our market here in PDX once you go into contract on a piece of dirt you will be 2 years or so before you can break ground and go verticle.. this is resi construction.in CA. it can be that and up to decades..

The two biggest breed biters are ankle-sized dogs.

The biggest ordeal is the Windows as well as the exterior paint.

@Miles StanleyPersonally I feel home warranties are more tailored towards first time home buyers - to make them feel better with the biggest purchase of their lifetime. 

I consider COC one of my biggest factors,  but cashflow definitely matters too.

Addresses one of my biggest concern.