Greetings cards written by Britain's late Princess Diana have sold for $3,800. The two cards - which belonged to former royal chef Mervyn Wycherley who worked for the royal family for 23 years - were expecting to fetch around $1,500 but a bidding war broke out when they went on sale at auction house Reeman Dansie in Colchester, Essex on Monday.

Auctioneer James Grinter said: "It's a very buoyant market, it has not been affected at all by the credit crunch. People would rather invest their money into something they can keep in their home and enjoy and which will hopefully rise in value."

A birthday card covered with pictures of condoms reached $1,900 after a fierce competition between telephone, internet and bidders in person.

In the card, the princess wrote: "Dear Mervyn, wishing you a VERY Happy Birthday, with much love from Diana X."

A Valentine's card with a cartoon bear on the front fetched $1,800.

Inside Diana joked to Mervyn: "Hey Valentine... not many men will receive a Valentine's card from Princess Diana... and you are one of them!!!"

Also included was a handwritten note in which Diana talked about her pregnancy cravings.

It said: "To Mervie, please could I have a bacon sandwich for breakfast and a much-needed rest from our friend the tomato! D."

A slice of cake from Diana's 1981 wedding to Prince Charles also went under the hammer, and fetched $400.

Other pieces of royal memorabilia on sale included a never-before-seen photograph of Queen Elizabeth wearing a pair of denim flared trousers. The shot sold to an unidentified bidder for $1,600 - nearly 20 times its estimate.

A ring worn by the late Duke of Windsor - King Edward VIII - sold for $15,600. The hold ring included the inscription "Darling Wallis", in honor of Wallis Simpson, the divorcee who sparked the 1936 abdication crisis when Edward relinquished the throne in order to marry her.

The auction raised a total of 80,200 pounds or around $122,800, with bidders coming from as far afield as America, Canada and China.