The Royal Household’s annual budget came under scrutiny yet again today after it was revealed that the Prince of Wales had spent £20,000 on a train journey from London to Port Talbot.

It is understood that where the Prince would ordinarily allow his Private Secretary’s team to take care of such mundane matters, he was intrigued to have a go at booking a train ticket online himself, with expensive consequences.

Ian Napton, a spokesman for GWR, the rail operator concerned, told us, “It’s easy for the public to book their travel arrangements at GWR.com, but it seems that, in this instance, the customer was inexperienced with our booking system. If he had bought an Off-Peak Supersaver ticket, split his journey at Didcot Parkway and used a Senior Person’s Railcard, he could have paid just £74.20, saving himself, let me see, nearly £20,000.”

Largely unaware of the value of money, the Prince appears not to have known that £20,000 was a bit expensive for a one-way ticket to Wales.

Conversely, all too aware that this sort of cock-up provides yet more ammunition to the anti-Monarchy brigade, senior aides have been seeking to play the matter down. Sir Giles Wilkinson-Giles, the Prince’s Private Secretary’s whipping boy was sent to face the Press. “His Royal Highness has saved the Taxpayer a considerable sum. Everyone knows that the Royal Train costs £60,000 per trip, so we are all quids in.”

First Group, owners of the GWR rail franchise, saw its share price rise by 3%.

Meanwhile, the Prince’s iPad has mysteriously been reported missing from his office at Highgrove, believed to have been placed discreetly under lock and key before the Prince, who is not known for travelling light,  discovered easyJet’s baggage charges.