Not just money but time spent getting an appointment, driving, waiting, picking it up. That's worth a lot of money and stress.
I would add as well that if you own a less popular model/capacity you may also have to wait for it to either be shipped to you or to the store. When I replaced my 11PM, I had to wait a week for the phone to ship to me. But, that was primarily because they didn't have the 512GB in-store. Fortunately, I was able to ride it out with my 6s+ for that week.
I would add and argue, the much bigger PITA is getting all your apps re-signed in, along with setting up financial apps, 2FA, etc.