Hopefully your one side will vacate properly and clean. 

The seller will lose some rent, potentially incur costs to evict, possibly costs to clean out the units depending on your sales agreement.

CA really cleaned up the fractional note business from my days of doing it in the 80s..

LTR tenants are required to have the home professionally cleaned. 

Spending on expensive upgrades is not the answer to improve your tenant base in this type of area.Keep the homes habitable, clean, and safe. 

I ASSUME you’re talking $400+ in extra expenses for providing water, power, sewer, gas, internet, communal area cleaning, and exterior maintenance.

Or do they just want to sign an agreement to move out in 30 days and you'll give them their full deposit in cash on move-out day, if they leave the place clean?

We have also found looking at actuals and Airdna numbers of the same property, that they're pretty well right on once we take cleaning fees out.    

My tenants are responsible for maintaining a clean property and for any requested pest control services.

Talk to other clients, go look at his current job site and see how clean it is, the quality of work, if the order of operations is making sense so far, etc.PS I'm a GC in the Nashville area and can take on a handful of clients in 2025 if you need me.