If you want to go an extremely cheap and zero work involved method, Amazon sells those wireless doorbells.

I have a online book-keeper lined up who will charge me $30/hr (cheap!)

And if I am the only one spending the time looking for them, because as you mentioned it's not easy and certainly not cheap, then I have a good chance of a winning solution for the seller and me.And once I get the initial list, pulling 50 leads a month is only a 5 hour job.

The work is the same to manage a cheap one bed and an expensive one bed (in fact, it may be more work to manage the cheap one, because lower paying tenants tend to be harder on apartments).

The cost of competent advise would be cheap when compared to making a mistake that violates the local laws.

I dont do furnaces , electric base board heaters , yes it cost more for the tenant , but they are cheap to replace and havent had a "no heat call " ever. 

They have a few different themes to choose from and it's fairly cheap.

It's relatively cheap considering what the potential return may be.

I know Home Depot sells a similar product with their Allure line, but I'm trying to position my place as a nicer rental so I don't know if Allure would be too cheap for the place.

A short cheap class, an easy test, and a small licensing fee.