An Andy Warhol portrait of Marilyn Monroe worth an estimated $200 million headlines this month’s spring sales in New York that collectors say are among the most anticipated ever.

Christie’s expects Warhol’s 1964 “Shot Sage Blue Marilyn” to become the priciest 20th century artwork when the auction house puts it under the hammer on Monday.

Not to be outdone, competitor Sotheby’s is offering $1 billion of modern and contemporary art including the second helping of the famed Macklowe Collection, during its marquee week in May.

“The excitement is certainly unprecedented,” Joan Robledo-Palop, a collector and CEO of Zeit Contemporary Art in New York City, told AFP, about the buzz surrounding this season’s auctions.

The 40 inch (100 centimeter) by 40 inch silk-screen Warhol is part of a series of portraits the pop artist made of Monroe following her death from a drug overdose in August 1962.

They became known as the “Shot” series after a visitor to Warhol’s “Factory” studio in Manhattan fired a gun at them, piercing the portraits which were later repaired.

Alex Rotter, head of 20th and 21st century art at Christie’s, has called the portrait “the most significant 20th century painting to come to auction in a generation.”

The current most expensive 20th century auctioned work is Picasso’s “Women of Algiers,” which fetched $179.4 million in 2015.

The auction record for a Warhol is the $104.5 million paid for “Silver Car Crash (Double Disaster)” in 2013.

Other highlights offered by Christie’s include Jean-Michel Basquiat’s “Portrait of the Artist as a Young Derelict” (1982), expected to go for more than $30 million, and “Untitled (Shades of Red)” by Mark Rothko, tipped to fetch up to $80 million.

The auction house is also offering three Claude Monet oil on canvases that are predicted to sell for upwards of $30 million each.

Rothko, Picasso, Richter 

“Every couple of decades you have a sale where the quality is so high that you don’t see all of this at once normally. This season really grew into one of those unique moments,” Rotter told AFP.

After selling the first batch of works from the Macklowe Collection — the most expensive to hit the market at $600 million — last fall, Sotheby’s will auction the remaining 30 items when its sales open on May 16.

Highlights include Gerhard Richter’s 1975 “Seascape,” estimated at up to $35 million, and Rothko’s “Untitled” from 1960 that has a high-end pre-sale estimate of $50 million.

Sotheby’s said its modern evening auction of 19th and 20th century works, including by Pablo Picasso and Philip Guston, is its “most valuable” in the category in 15 years.

Picasso’s “Femme nue couch,e” is appearing at auction for the first time, and Sotheby’s expects it to fetch more than $60 million. Other highlights include a Monet view of Venice tipped to fetch $50 million.

Brooke Lampley, head of sales for global fine art at Sotheby’s, said she expects records to be broken across categories.

“The art market is very strong. That’s why we see such an amazing array of works on offer this season,” she told AFP.