Hmm I'm about to book a Delta flight for the first time too. Won't the $25 show up in the bill when you pay? It's not something you pay upon check-in right?
Matters because acc to the FAQ/T&C the rest of my family (up to 3 of them) get a free checked bag too. That's $100.
So how do you make sure it reads as $0 and not $25?