USD 300 is the rock bottom minimum (for their cheapest set menu with no wine or extras -- however that is a very lavish meal so no extras are required). Is it worth it? Absolutely. I would skip lunch for a month in order to eat there (or the French Laundry in California, or Le Bernardin in NYC, or maybe a dozen restaurants in the world). Thus: special, a worthy experience, a must if you love food, but not unique and not the only chance of a lifetime.
An interesting aside: these meals are actually good value compared to lesser great restaurants (the 1-star level for example). The price is not proportionately greater with the quality and even cost of production (many 3-star restaurants lose money on the restaurant operation, it is the rest of the chef's ventures that subsidize the 3-star restaurant -- hard to think of a $300 meal as being priced below cost, but that is often the case!