Jennifer Aniston spends $450,000 on painting

He bids, she buys!

Jennifer Aniston was the winning buyer at Christie's glitzy "Artists for Haiti" auction in NYC on Thursday -- where beau Justin Theroux did the bidding on her behalf.

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Actor-screenwriter Theroux, 40, helped his love, 42, snag American artist Glenn Ligon's "Stranger #44," an abstract 2011 work of oil, charcoal and graphite on canvas that seems to match his downtown hipster tastes.

At the auction, "Stranger #44" was estimated at $150,000 to $200,000.

But Aniston helped shatter the record for sales of Ligon's work, spending a whopping $450,000 on the 72" by 60" painting, an Artists for Haiti rep confirms to Us.

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Reports : "Aniston, who was in the room, clapped enthusiastically after [Theroux's] winning bid."

Benefiting health and education initiatives for Haiti, The "Artists for Haiti" auction -- artists donated their works for the cause -- was co-organized by Ben Stiller, and raised $13,662,000.

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After the auction, Stiller, 40, and his wife Christine Taylor hung out with Theroux and Aniston for a late dinner at Il Cantinori. "They seemed to be having a lot of fun with Ben and his wife, like old friends," a witness said. "Ben paid for everyone," the witness adds.

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Stiller co-starred in "Along Came Polly" with Aniston and co-wrote "Tropic Thunder" with Theroux.