So, what makes a piece of art worth $106m?
This week, Picasso's Nude, Green Leaves and Bust goes on public display in the Tate Modern for the first time in over 50 years.
The painting was bought by an anonymous bidder at Christie's auction house in New York last year for a staggering $106m, making it the most expensive ever sold at auction.
What do you get for 100m bucks? Well, it's a Picasso, painted at the height of his powers in 1932, so it's not half-bad. It was, however, completed in just one day in 1932 (nice work if you can get it) and portrays his mistress, Marie-Therese Walter, nude in front of a bust of herself.
This was the first time Picasso had painted Walter so identifiably (up until that point he had concealed the affair from his wife, Olga).
The new owner of the painting has loaned it to the Tate for at least two years and it is well-worth seeing, not least because it is not certain when it will be exhibited again. Until now, the last time this painting was publicly presented for viewing was at Picasso's 80th birthday celebration in 1961.
Why has it become the world's most expensive painting? Ian Whyte, managing director of Whytes Auctioneers in Dublin says: "When valuing the pictures of any artist, supply and demand is the first rule. Obviously, this is a unique painting so supply is limited.
"It's also from Picasso's prime. Artists tend to reach their prime somewhere between 30 and 50 -- they're painting at their best.
"Having said that, Picasso went on to paint great pictures in his 70s and 80s, just like Jack Yeats."
Subject matter is another important factor. "The work should be typical of the artist. Let's say you have an artist who normally paints landscapes and someone walks in with a figure study. It's not typical."
Which might lead you to believe it would be worth more, being a rarity. Not so. "If somebody is going to buy one painting by that artist they might want to buy something typical."
Most people will want something that represents the artist, not least so people can look at the painting on your wall and easily identify it as the prestigious artist it is by. Which is where specialist collectors can swoop in and get atypical work by the favourite artist for a song. "They will get them quite reasonably," says Whyte. "The more typical of the style of the artist it is the better. This Picasso would be typical of him at his best."
There's not really any debating the value of this Picasso -- painted at the height of his powers and marking a significant period in both his personal life and his professional life.
But can cost be equated with value? "There's an element of trophy hunting," says Whyte. "If you're a multi-billionaire you're in competition with other multi-billionaires. It's a question of having the best Picasso in the world."
One factor that is not so important when valuing a painting is size. That is one thing that changed during Ireland's property boom.
"Large works are getting less money than small works now because people just don't have enough room on their walls. Larger works would have previously been bought by businesses but now those businesses don't have the money . . . but the person who can afford to spend $106m on a Picasso probably won't have to worry about wall space."