We have zip codes that have lower and and higher end areas within the same zip so not a good marker to use.Going along with that a lot of the neighborhoods are very street by street or change pretty quickly by block, so you have to be aware of that.

Rates are also better with these than with an investment loan.There are a couple of investment loan programs available that offer 10% down as well with no PMI, but they have slightly higher rates.

I've seen properties on a lake or near a park or popular trail that will consistently get higher rent. 

Traditional IRA withdrawals are taxed as ordinary income, with a 10% penalty if under 59½, potentially pushing you into a higher tax bracket.

The smaller homes can be obtained in nicer areas while demanding higher rents with section 8 compared to the private market.

Being a real estate professional allows you to treat the income as non-passive, allowing higher high income tax payers to pay less in taxes.

Higher? 

I suspect build cost in CA are closer to 400 a foot than 200 like many other areas and of course far higher for the custom homes.

Just because your guest paid one price a year or two ago doesn't mean you haven't had higher expenses or more traction in bookings to add to demand.  

So, it's still a viable way of investing, but does not have the same scale of success in today's economic environment in higher appreciation markets.