It’s impossible to avoid wine markups at fine dining restaurants — even if you’re a celebrity and one of the richest people in the world.

Amazon CEO Jeff Bezos reportedly forked over over $4,000 for a Burgundy Grand Cru while celebrating his engagement with fiancé Lauren Sanchez, according to People. The pair was seen indulging in the bottle, which People reported to be an off-menu 2015 bottle of Dugat-Py Grand Cru, at La Petite Maison in Cannes, France.

While the price of fine wine tends to fluctuate and can cause high markups at fine-dining establishments, some wine pros are claiming that Bezos overspent by thousands. An anonymous source, who claims to know the history of this bottle, told the New York Post that Dugat-Py Grand Cru last sold for a little over $600 at auction last year. (It’s worth noting that Wine-Searcher estimates the bottle to average around $3,500 at retail.) Restaurants typically price bottled wine at around two to five times the wholesaler cost.

Social media users quickly found some joy in the billionaire’s potential misstep. Parcelle Wine Shop, a wine bar and bottle shop in Manhattan’s Lower East Side, noted the high price tag in a playful Instagram post suggesting Bezos didn’t know the real value of the bottle: “Wine fact of the day: Bezos knows less than you and got mega ripped off in France.” Users were quick to joke that the CEO, who has a net worth of nearly $143 billion, could likely afford the markup.

Still, even billionaires should pay attention to wine lists.