Often it's a requirement if you have your event in a hotel. The hotel will sometimes have restrictions on who you can use to cater for breaks or lunches.
People expect coffee or drinks during breaks and will complain loudly regardless of the registration fee. $7-10 per person for a coffee break is not uncommon.
Minor point that made a couple speakers happy the first year - I had small break service (venue-speak for snacks/drinks/coffee) in each presentation room, vs out in a main lobby area. Apparently they like being able to get set up in a room then grabbing a quick cup of water before speaking without having to navigate back to a larger common area. Who knew? :)
People expect coffee or drinks during breaks and will complain loudly regardless of the registration fee. $7-10 per person for a coffee break is not uncommon.