Even billionaires -- even real live Dallas ones -- have bad days at the office.

Three Texas megamoguls have suffered an assortment of degradations, embarrassments and setbacks in recent weeks that, taken together, make the on-screen reversals of J.R. Ewing or Alexis Colby seem mere irritations.

There's no connection among the three. And it's quite possible that nothing of cosmic importance is hidden beneath the tribulations of H. Ross Perot, Clint Murchison Jr. or the Hunt family, all of Dallas.

But read on. These stories will probably make you feel better.

Start, in ascending order of gravity, with Perot. Last Tuesday, when he announced that he'd bought a 6,000-acre tract north of Dallas for $110 million, everyone figured it was, in local parlance, a done deal.

Perot didn't say what he was going to do with the land, but ever since he cashed out of his computer management company, EDS, for a cool $1.5 billion last year, he's had some bucks burning a hole in his pocket.

The next day, Wednesday, the seller of the land, Gulf Broadcast Co., announced that it had indeed sold the tract -- to Gibraltar Savings Association of Houston, which had paid $130 million.

"If that's the case," Perot said, archly, "then they sold the same land twice.'

Gulf Broadcast said Perot merely had submitted a bid on the land. Perot said he had a confirmed sale: "I have a great deal of experience buying land, and I certainly know the difference between buying and bidding."

Perot has more limited experience, on the other hand, buying museums. But that hasn't kept him from getting into his second little flare-up of the week, this one involving his effort to move the Museum of the American Indian from Manhattan to Dallas, which is trying to transform itself into a "city of the arts."

This month Perot reportedly wrote the financially troubled museum, which houses the world's largest collection of Indian artifacts, to propose a deal: He'll give it $70 million if it moves to Dallas.

The museum is weighing the bid, but it may be bound by a stipulation in its original charitable trust that obiglates it to benefit the people of New York state. Damn Yankees!

Perot isn't talking. His associates hint that both matters may wind up in court.

Court is also where we find the set-upon Hunt family, which, according to Forbes Magazine, has turned out four of the nation's 10 richest people: Nelson Bunker Hunt ($1.4 billion in net worth), Margaret Hunt Hill ($1.4 billion), Caroline Hunt Schoellkopf ($1.3 billion) and W. Herbert Hunt ($1 billion).

The Hunt family was stung this month by an Internal Revenue Service order to pay more than $200 million in back taxes for 1972 to 1980, an order that family lawyers are contesting in 18 suits.

Wednesday, Hunt International Resources Inc., a holding company of brothers Nelson Bunker and W. Herbert, told the Securities and Exchange Commission that it was in default on $295 million of debt and unlikely to repay it all. The company, which operates a large sugar refinery, is one of several family holdings under severe pressure from deflated commodity prices.

The Wall Street Journal estimates that the two brothers and a third, Lamar, have seen their net worth decline by $4 billion in four years, to an estimated $1.6 billion.

On the other hand, Bunker once confessed that he had no idea how much he was worth. "People who know who much they are worth generally aren't worth very much," he observed.

Our third Texas tycoon in distress is Murchison, founder and former owner of the Dallas Cowboys. His story is by far the saddest.

Murchison has been so besieged by creditors, all suing over far-flung, highly leveraged deals that went sour, that, in order to keep the wolf from the door, he transferred his private residence to the ownership of a dummy corporation this month.

The sad thing about Murchison, 61, son of legendary oil wildcatter "Big Clint" Murchison, is that his travails appear to have been brought on by a brain disorder -- cerebellar degenerative disease -- that has confined him to a wheelchair, slurred his speech and left him able to sign his name only with illegible scrawl.

Doctors say he is still alert; but associates say that as his physical condition has declined, he has relied more on outside advisers, who have led him astray.

Ironically, his sale of his beloved Cowboys last summer for $80 million seemed to have made matters worse. He used the cash to liquidate some of his debts, but the publicity made other creditors nervous and "created an effective run on his estate," one adviser said.

Murchison's father, one of the giants of Texas oilfield lore, is known for his pithy sayings about money -- one of which seems especially ironic now: "Money is like manure. If you spread it around, it does a lot of good. But if you pile it up in one place, it stinks like hell."

Young Murchison spread it all over -- in resort condominiums in Key West, Fla., in construction companies in Hawaii, in Washington's ritzy 42-acre Hillandale development on Reservoir Road across from Georgetown University Hospital. All have had to be auctioned or sold -- and indeed, the whole Murchison empire is now in bankruptcy court.

What to make of all this?

"It's a tough time to be a Texas billionaire," offerred William E. Gibson, chief economist at RepublicBank Corp. in Dallas. "The downturn in the energy buisness is a factor, plus at the same time, these people got into . . . deals that seem to have downturned as well."

For the rest of us, we probably read such sagas to satisfy a deep yearning of the human spirit that George Mitchell, mutlimillionaire (and quite solvent, thank you) independent oilman from Houston, understands all too well.

"My favorite cartoon," he said, "is of a novice skier going up the chair lift for the first time, and looking down at an instructor doing graceful S-turns on the terrifying slope below.

" 'Fall, you bastard,' she mutters. 'Fall.' "