It seems to be no small irony that an original copy of the 1733 Poor Richard's Almanack, the first in the series of annual volumes penned and printed by Benjamin Franklin, sold at a Sotheby's auction last week for the princely sum of $556,500.

Franklin, of course, is America's favorite apostle of thrift. It was he who, in a later edition of the Almanack, issued a warning that the anonymous buyer of the rare book evidently ignored: "Buy what thou hast no need of, and ere long thou shalt sell thy necessaries."

But Franklin himself probably would have enjoyed the irony.

True, he liked to portray himself as the archetype of republican virtue, especially when it came to frugality. In his Autobiography, he wrote of becoming a vegetarian while apprenticing for his brother to cut the cost of his meals, and of his disapproval when his wife, Deborah, replaced his simple, pewter porridge spoon with a silver one.

In reality, though, especially as he grew older, Franklin wasn't the thrifty hero he often claimed to be. He positively embraced his sybaritic side.

While living in London from 1763 to 1775, he shipped crates of luxury goods - silk blankets, fine china and crystal, special material for curtains, damask tablecloths - back to the house he and Deborah were building in Philadelphia. In addition, as the historians Claude-Anne Lopez and Eugenia Herbert wrote in their book The Private Franklin: The Man and His Family, "the middle-aged Franklin, as generous and expansive as the young Franklin had been tight and guarded, sent presents left and right."

One was an unusual edition of the writings of Virgil, which Franklin donated to Harvard University. That makes me think he would have appreciated the pleasure of the bidder in last week's auction, who clearly treasured the old patriot's Almanack just as Franklin had prized his copy of the Roman poet's work.

The Sotheby's sale also would have appealed to Franklin's vanity. He struggled to temper his pride even as a young man, when, with characteristic ambition, he embarked on "the bold and arduous Project of arriving at moral Perfection." According to this story, the young Franklin wrote up a list of 13 virtues - including frugality, industry, moderation, and humility - and resolved to master them one by one.

Franklin had the hardest time with humility. But he eventually forgave himself. Ever the pragmatist, he concluded that some imperfection was preferable to complete and total virtue, since "a perfect Character might be attended with the Inconvenience of being envied and hated."

So I have a feeling Franklin would have been tickled at the thought that his modest little Almanack, which sold for about a nickel in its day, fetched the second-highest price on record for a book printed in the United States (after George Washington's copy of the Federalist Papers, which went for $1.4 million).

As Poor Richard once opined, "If you would not be forgotten as soon as you are dead and rotten, either write things worth reading, or do things worth the writing." Richard's creator, Benjamin Franklin, did both.

Lauren Weber is the author of the forthcoming "In Cheap We Trust: The Story of a Misunderstood American Virtue." Her Web site is www.laurenweber.com.