LONDON — Mattel Inc.’s original Barbie doll, a brunette in a swimsuit and sunglasses, sold for twice its top estimate at a Christie’s International auction in London on Tuesday. Many of the aging plastic figures, marred by oily faces or green ears, went at discounts.

Barbie model no. 1, priced at $3 at retail in 1959, took $5,457 from a gold-haired woman in the room, even though the doll’s nail polish was chipped and her legs mottled. The auction raised $210,394, beating Christie’s presale estimate only after its 20% commission was added.

It was the first solo auction for Barbie dolls, which were launched in 1959 by a co-founder of Mattel, Ruth Handler, and now have retail sales of about $3 billion a year. Most of the initial 50 lots were knocked down at hammer prices below their low estimates to dealers and collectors. A problem for collectors of vintage Barbies and some 20th-century designer furniture is that plastics deteriorate over time.

Some plastics soften or harden after 10 or 20 years; others remain stable for as long as 40 years, “if protected against environmental influences,” said Ulrich Guntram, chief executive officer of Axa SA’s art insurer, which insures vintage Kaethe Kruse dolls and plastic designer furniture.

Two 1965 “American Girl” Barbie dolls, dressed in striped tops and green shorts, took $952, compared with a top estimate of $567, from a woman who wore a mauve quilted jacket and glasses.

“I’ve always wanted them” for my collection, she said, declining to give her name. One Barbie no. 3, with brown-stained ears and smudged lips, sold for $181, less than half of the top estimate.

Barbie is collected by about 100,000 adults and teenagers, according to Mattel. Christie’s auctioned a Dutch holding of about 4,000 dolls — many in good shape — at two sessions on Tuesday.

A Mattel spokeswoman, Jacey Bunker, said the dolls’ lifespan “depends on how well they’re looked after. If they’re kept in their original packaging, they can last for decades. Earrings can discolor the ears, so we recommend that they be taken out.”

Green ears, sweaty faces, and smudged lips were common catalog descriptions. Chewed feet, thinning hair and missing fingers or tips of noses occurred, too. Barbie no. 1 beat Christie’s previous highest price for the original model, set in 1999, of $5,288.

Barbie, with her designer clothes and accessories, has been called an emblem of American suburban materialism by sociologists.