A british couple saved thousands of pounds yesterday when they flew to Australia to celebrate the millennium with friends using air tickets booked 16 years ago. Peter Harrison and his wife Marguerite, who are now both 76, admit they took a huge risk when they negotiated two first-class tickets to Sydney at 999 pounds ($1'613) each. But the gamble paid off as the couple boarded their British Airways flight at London's Heathrow airport because the tickets would have cost 5'773 pounds each if they had been booked now. The tax-free investment in their fares has turned out to be more lucrative than putting the money into the stock markets, the Post Office or leaving it to grow with a high-level of inflation. Although there was no guarantee of a refund in the event of the deaths of either of the couple, Peter Harrison always knew he would be on the flight. I had no intention of dying beforehand, he said.