Mum Sarah Quinlan learned about her pricy purchase when she came to the computer to check the e-mails.

“I saw an e-mail from TradeMe saying I had won an auction, and another e-mail from the seller saying something like ‘I think you’ll love this digger’,” The Times quoted the stunned mother as saying.

That she couldn’t remember having bought anything of the kind, Sarah Quinlan assumed it was a Lego digger for her kids. But when she saw the price – 20,000 New Zealand dollars ($12,200 US) she “got the shock of [her] life.”

Full-size excavating digger Kobelco (Photo from site kobelcoamerica.com)

She asked her husband Reid what a Kobelco was and if he had bought a digger. But the answer was negative. The only other possible variants were the kids, one of them a boy aged 18 months. The parents realized it was Pipi, who uses the computer to play toddler games.

Reid and Sarah Quinlan had a talk with their small daughter having explained how her unawareness cost her family a huge sum of money, enough to buy 20,000 ice blocks. This impressive example made the girl realize her mistake.

Sarah rushed to call TradeMe and the seller to tell them that a mistake had happened and refused the purchase.

After realizing that three-year-old Pipi was smarter than her parents thought, they now keep the computer logged off and out of her reach.