The answer to your question is heavily dependent on multiple factors such as being a good manager of things generally speaking, how well you do your tenant screening, how comfortable you are with bookkeeping (if you are going to do it yourself), if you have a good selection of service providers in the area etc. 

I live in the Pacific Northwest, I'm a bit priced out of the market, I'm attracted to buying a duplex or fourplex in some state in the Southwest or Southeast where I can better afford to buy, I would like to move there and live in one of the units, but it seems like an overwhelming project to decide where to buy it seems there are a lot of factors involved and it's difficult for me to come to a decision.

But if it's just a house for you to live in, not an investment, then financially speaking you can't do better than living for free since the home you live in generally tends to be a wash or lose money when you factor in everything - maintenance, furnishing, repairs, etc. 

Risk acceptance and goals are the two main factors that are unique to you.

If you look at the analysts from the major investment firms, banks and hedge funds, many of them are discussing that a more realistic number for investors to expect in equities (stocks) for quite a long time will be closer to 7% and this is before the index fund expense ratio and inflation is factored in.

Same builder, same house, in same neighborhood for example could back to a busy main street in the entrance of the neighborhood, could face West where people prefer East facing, be the house that everyone drives by and lights shine in the front windows when you enter the neighborhood, could back to power lines in the back of the neighborhood, could be next to the community pool, could be on a corner with a bigger lot, and a host of other factors go into pricing....not just size.The 3 main sources that most sellers use for size are tax roll, appraiser, or builder's plan. 

Over the the episodes from the past two weeks, David from the BiggerPockets podcast has brought up that real estate will be harder and harder to from the "small guy" to get into each year due to factors like: inflation, hedge funds being hyperactive in the market, the lack of supply and high demand causing an increasingly competitive market, real estate being a more attractive investment for our current economic condition, etc... 

That would factor into your purchase price and ROI.Good luck....

You don’t have all the factors you had in 2008 with plummeting prices, what people are in trouble will likely not be upside down and simply be able to just sell their houses on the open market.  

Credit score would also be a factor, but you can easily add a partner to these loans to shore up where ever you may be lacking.