I'm envisioning something that would be a combination of a contact management, budget and expense tracking, document portal, and task tracking system.

Will get access to Buildium portal, along with periodic inspections and a nifty maintenance tracker. 

I use TenantCloud as my online property management portal with my tenants.

Whether the Fair Market Rent values listed in www.huduser.gov portal would be closer to reality for most of the properties within Maricopa County.

I know the markets of liberty city, Brownsville, allapattah and el portal intimately so I’m always out there hunting too.

The most succinct history I've found (there's a lot to unpack) is the walking tour from Cultural Tourism DC https://www.culturaltourismdc.org/portal/dc-neighborhood-heritage-trailsPrices jumped up just as the Wharf was being completed, but haven't really gone anywhere since then.

I'm looking for something cost effective that tenants can log into and pay through an online portal. 

You can then give tenants an online portal for payment.

Most property management companies also have an online payment portal, but then you pay them a monthly fee- usually it is around 7%. 

We also are paperless, all docs are completed online, owner Portals etc so it doesn't matter your location you will stay informed.