That $3 million Caravaggio is looking like a bargain compared to an $81.9 million Andy Warhol.

This week at the Old Masters sales in New York, when as much as $200 million of 15th-to-19th-century paintings, drawings and sculptures are on offer, the auction houses will try to slightly narrow the disconnect between the record prices commanded by postwar, modern and contemporary art and the much lower estimates for the older works.

Old Masters, the most popular category until the 1980s, is now a small part of the art market, and drumming up renewed interest won’t be easy. The group in 2013 accounted for 10 percent of the value of the art market, with just over 1 billion euros ($1.1 billion) in sales, according to European Fine Art Foundation.

“There’s no real connection between the two markets,” said Otto Naumann of Otto Naumann Ltd, a New York gallery that specializes in Old Masters. “They’re two totally different fields. They both just happen to be called art.”

That’s not stopping auction houses from trying. One of the most expensive lots of the week at Christie’s is a 16th century portrait painting by Agnolo Bronzino, estimated at $8 million to $12 million, which failed to sell at the same auction house in 2013.

Christie’s catalog compares the work to Warhol’s portrait of Mao, and Lucian Freud’s painting “The Brigadier.”

Sculpture Prices

An oil painting of a vase with flowers by the 16th century German artist Ludger Tom Ring II is compared in the Christie’s catalog to Jeff Koons’s “Small Vase of Flowers,” a polychromed wood sculpture from 1991. Ring’s still life is estimated at $400,000 to $600,000. The Koons sculpture sold for $2.3 million at Christie’s in New York in May 2005. More recently, a 12.5- foot-tall orange stainless steel sculpture by Koons fetched $25.9 million in November in New York at the same auction house.

Some dealers aren’t convinced such promotion will work.

“The disparity between Andy Warhol and the Old Masters is just too wide to bridge,” said Richard L. Feigen, the Manhattan dealer and Old Masters expert whose gallery bears his name.