Sell SFR for a duplex with same rental income 1/3 value

[Bryan M.]

We own a SFR in Oakland, CA. It rents for $4k/month - 2 bed / 1.5 bath. Approximate value (according to Zillow) $1.1M.

30 miles east of us in Pittsburg, CA there is a duplex currently for sale for $430k with rents of $3.9k. 

Now on to my question. If we can get nearly identical rents with 1/3 of the property value should we sell our SFR and buy the duplex?

Thanks,

Bryan