You only overpay for a buffet if the price is higher than you would pay for what you eat a la carte. I've often found buffet breakfasts to be a good bet outside of North America, where coffee / juice refills are not standard - a couple of glasses of grapefruit juice (at a couple of pounds each), a couple of coffees (at a couple of pounds each), maybe a croissant with jam (4 pounds perhaps) and a bowl of fresh fruit (5 pounds perhaps), or scrambled eggs with toast and a couple of grilled tomatoes (12 pounds on the bill in my wallet), soon means that if there is an 'all in' buffet price of, say, 15 pounds, it can work out good value.