Not only is it cheaper but with inflation and artificially suppressed interest rates the monthly payment is ~$600 less per month!. 

Hood systems/fire suppression also very costly.You mentioned long term tenants for all units, but what are current and historic sales for commercial spaces?  

@Lamont Marable find an investor friendly agent and you can get all of these questions answered for free from Someone that wants to earn your business.Adding units is extremely difficult if there is not already a fire suppression system in place or fire walls present.

This cycle continues to suppress available rentals. 

Not sure if it matters, but the whole building and all units have a fire suppression system and other things needed for a commercial building since the 1st two floors are commercial, the city made us make the entire building outfitted with a fire suppression system and wireless notification.

What fixtures are there already: hood/fire suppression, walking cooler/freezer?  

With the market the way it is, selling a property just to buy another is probably an expensive option, especially in Huntsville which seems to have suppressed returns right now (I've only analyzed a handful of deals from there though). 

Been there done that.Our town decided that all multi's required a fire safety audit & the Fire Sprinkler System we were required to instal eliminated the need for many expensive tedious upgrades to 'suppress' a raging fire.

However, developers can sometimes overbuild such that all of their new apartments suppress rents and occupancies of their competition.

Local laws can not suppress HUD regulations.