Do I owe Jack Keller Inc., REALTORS anything at closing?

No — with one condition.

• If you sell your home to a buyer who has no real estate agent: You owe us nothing at closing. Your only cost is the flat fee you paid when you listed.
• If the buyer is represented by a real estate agent: A small fee will appear on your closing statement next to our name, below the "Commissions" line. This fee is paid by the buyer's agent. It does not reduce your proceeds by a single dollar.

Either way, you pay only your upfront flat fee. We do not charge sellers a commission or a closing fee — period.

See also: [Why is there a fee on the closing statement?]