Getting ready to sell a 4-plex - trying to judge the market/price

[Margaret Johnson]

Getting ready to list a four-plex for sale (probably first week of June).  Trying to get an idea of reasonable expectations.  We've never sold a four-plex before.  

I'm told that for single family homes, investors want the rent to be 1% of the purchase price.  (Like a $200k house would have to rent for $2000 a month).   

Is the formula the same for a four-plex? Or are the numbers different?

We are are looking to list at $550k.  Real estate agent estimates rents could be $4800 total a month.  (So if the 1% rule applied that would be $700 a month below). Is that a problem?

Four-plexes are considered rare and desirable in our area.  (Denton, Texas - north side suburb of Dallas/Fort Worth). (Building is within 4 miles of 2 Universities. Public bus stop within a block). 

The building has been fully updated within the last 4 years, all new appliances in all kitchens (included).  Older washers and dryers in all units included.  No pending projects or known issues. 3 units have good tenants in place ($3200 total current rent) and 4th unit is currently owner occupied so not paying rent, but is the best unit). Based on the existing mortgage, building cash flows $600-$700 a month with 3 of the 4 units rented. 

Does our pricing sound reasonable?  (Only reason to sell is to access the cash equity to pay off debts and reinvest). Any ideas of what we can expect when this goes live?