It may be that the art world is becoming a little blase about the record-breaking prices for art works at auction, in this day when one record tops another with seeming regularity. But yesterday's sale of an 1861 work by Fredric Edwin Church for $2.5 million clearly was a surprise.

"Why 20 years ago, when Church seemed to be at his lowest ebb of regard, you could have grabbed one for $4,000," declared Bill Williams, the National Gallery's education director. "I thought of saving my money and buying a Church while I was in college, but of course I was a fool and didn't."

The subject of Church's "The Icebergs" kept coming up last night at two parties attended by many members of the country's art community. During one, at the Egyptian Embassy, Ambassador Ashraf Ghorbal gave his country's ornate Order of the Republic to the museum directors who shepherded the Tutankhamun exhibit through its three years in this country. Then some of them went on to a National Gallery reception opening the exhibit of 17th and 18th-century terra cotta sculptures from the collection of New York psychiatrist Dr. Arthur M. Sackler.

The biggest question about the Church painting was, who bought it?

"We sat around trying brainstorm it this afternoon," said J. Carter Brown, the Gallery's director and one of the eight persons decorated by the Egyptians. "We tried all kinds of guesses. Even that it might be a wealthy donor who might give it to the White House."

Someone interrupted Brown asking whether there was wall space at the White House for a 64-by-112-inch work. And Brown granted that "I'm not sure they have the place."

A major figure in the art world who preferred not to be quoted by name, wryly suggested, "It might have been Armand Hammer, but I doubt it. He would be gloating so much we would know it." Several suggested that "The Icebergs" would make a natural pairing with the National Gallery's large Church, "A Morning in the Tropics," but Brown contended he knew no more than anyone else.

At the Egyptian decoration cermony Ghorbal singled out Metropolitan Museum director Thomas Hoving for greatest praise, as "the man who really had the dream and the perseverance to see it through."

But later in conversation Hoving, who conducted the negotiations with the Egyptians that led to the exhibition, threw the initial credit to an unexpected party.

"Most people don't know it, but it was Nixon. He was on that trip to the Middle East not long before he had to resign. He saw some of the objects and the next time he met with President Sadat, he asked for such a show, and he got it," recalled Hoving. "We didn't talk much about him for most of the years of the show, for obvious reasons."

The decorations the museum directors wore after yesterday's ceremony were lavish crests hung on red, gold and green ribbons around the neck. "These are meant to be worn with tails, so I'm going to go out and buy the first pair of tails I've ever owned," said Hoving.

Each person also received a larger version of the same crest meant to be worn over the left chest with formal uniforms. "I haven't had a uniform since I was in the Marines," said Hoving, "but the ambassador said my wife could wear it on a pendant instead."