What a great challenge - anyone who is renting at a property with those rents would probably not want to be bothered (high-touch but once the lease is signed, "leave me alone, I'm busy and important.") -
Brokers, realtors, locators, etc. come to mind. These prospects probably value word of mouth, but may not be seeking it out on their own.
Outreach to HR would still work here - at $3K to $10K per month, this could be companies bringing in consultants or temporarily relocating their fix-it experts; they need apartments they know they can trust, who will always get it right.
Consulting firms, hospitals -