As of 2019, how much does the most expensive bicycle cost?

The Butterfly Trek Madone, an artwork utilizing a bicycle by Damien Hirst, became the world's most expensive bicycle when it was bought at auction for $500,000. It was designed by Hirst, who used real butterfly wings that were placed onto the actual frame and rims of the bicycle. The bike had been ridden by Lance Armstrong in the 2009 Tour de France.

Butterfly Trek Madone was auctioned at Sotheby's for the Livestrong Foundation. Armstrong's excitement was evident on Twitter when he tweeted during the auction that the bike had gone "for 500,000.00!!! Half a million bucks!!!" The event that the Butterfly Trek Madone was being presented at was the "It's About the Bike" auction held on 1 November 2009 in New York City. The auction was held to raise money and benefit the Lance Armstrong Foundation's cancer research, awareness, and advocacy. At the auction, a total of $1.25 million was raised. There were about 20 renowned artists that were asked to utilize their expertise to create a unique artwork to be showcased and ultimately auctioned off. It ended up being Hirst's Butterfly Trek Madone that sold for $500,000.00.