The only costs are hourly wages to an assistant to respond to the tenants if something comes up like a question about the online payment portal system or something else.

I found it researching online after many months.

@Matt Wan Many lenders require wet signatures on at least the Promissory Note but if yours does not, as a US citizen you could do the entire signing anywhere on the planet with a good internet connection + mic + camera via Remote Online Notarization (RON) for less than $200.If wet signatures are required, the answer then depends upon what foreign country you are in.

Networking with local real estate groups or online forums could help you find recommendations for PM companies that have a proven track record in Birmingham 

However, if all they offer is general info, I think you can find most of it yourself in Bigger Pockets and other online sources.

Just shop around online, look for properties similar to yours, add them to favorites and watch them to see how long it takes for them to rent.

There are also many online calculators you can use if you do a search for them.

I didn’t know anyone in Alabama, so I called a few agents I found online and ended up picking one from BiggerPockets.

I've found conflicting information online.

If you want to send me a DM I can send you a link to run an easy online quote