I paid roughly $46 in the USA for a breakfast buffet once. It was a day when I was hungry and very short on time, and the breakfast buffet offered numerous high-quality foods that rivaled many dinner buffets. Other than in extreme cases like that I would not spend so much for breakfast.

Breakfast at international business hotels is pricey. I usually don't see it quite as high as $46 US but I'd say $25-35 US is fairly common. That's the a la carte price. Many guests spend less by buying a package room or getting it as an elite benefit. That's one of the reasons I stay with hotel chains where I have elite status even though their prices are higher than the local competition-- the value of free breakfast and/or evening lounge food can be considerable.