IMO it depends on how much time one spends in the resorts. DH and I were only ever at our resort for breakfast, and my breakfasts came with drinks (since I got kids meals lol). DH didn't get the same meals I got, so his didn't come with drinks... so for him, the mug might have made sense if he hadn't wanted to buy a Monster for his morning caffeine. So, we didn't buy the mugs and I honestly don't think they would have saved us any money, given the details I just laid out. For people who go back to their rooms for a mid-afternoon break, get back before the food court closes, or drink fountain drinks (or anything else that is served in that mug) with breakfast, it does save money if being used for several days.