Make sure your agent is communicating with you ans explaining things if you ask. Don't be afraid to ask your agent a question. We do this all the time (well, some of us) and sometimes forget that our clients maybe last bought a home 15 or 20 years ago, or this is their first. That's our job, to answer your questions, give you advice, get you the best deal possible, and attempt to give you as smooth of a transaction as possible.
Best of luck!
My read of this is that the broker is expecting a 5% commission. If the listing brokerage offers it, then it will be included in the sales price. If they are not, then . . . I think the difference would have to be made up at closing.
But - talk to your broker. Communication is key, and if you can't discuss this with them . . .
All the best,