Each housing authority (HA) provides a voucher amount determined by bedroom and some further define it by zip code or city within their covered area.

It likely is out of date as to cost as this info is quite old (my guess is 5 years but it could be longer):- Rent Recovery Service: offers flat fee service starting at $20. 3 letters start at $30.

This is a FREE service provided by the bank, and we have used this account for about 15 years or so. 

@Garry LawrenceDevin Moreno has a bunch of videos on rent-by-the-room strategy in Baltimore on hisYoutube channel.

You can do an exchange for less than the full amount, but you will owe taxes on the boot.

That's like asking how much it costs to buy a car. 

I recommend you do it yourself, @Helene Zernik.

What kinds of deals do you prefer?

Out of 4 tenants, only one has abided by the lease. 

There is already at least one request with a lot of votes for this feature, and you can allocate your "votes" to it as well...maybe Buildium will start work on it after it gets a few hundred more votes.