England rugby fans have been urged by star forward Courtney Lawes "not to remortgage the house" to get tickets for the World Cup final.
Prices have spiralled on reselling sites for Saturday's clash against South Africa in the Nissan Stadium in Yokohama.
Tickets are being offered at several times face value, ranging from £1,500 to a high of £12,800 on some sites.
But fans are being warned by world cup organisers they run the risk of being turned away at the gates if they have purchased tickets through these sites.
Giant forward Lawes said fans should not pay over the odds and told ITV News that there would be a good chance to party after the match if England brought the Webb Ellis Trophy home.
"I think if you're trying to get hold of tickets, don't pay extortionate (prices), don't remortgage the house to get yourself in the stadium," he said.
The Northampton Saints international said he was relishing fronting up against the Springboks - and matching fire with fire in the battle with their own forward pack.
Tens of thousands of England fans have been trying to secure a seat for the final, following the brilliant win over the All Blacks on Saturday.
Demand has also seen the cost of flights to Japan spike with non-stop travel from London Heathrow leaving on Wednesday and coming back Sunday hitting a minimum of £1,582, according to online searches.
The most eye-watering increases can be found searching for tickets, with online resellers charging anything from £1,500 right up to almost £13,000.
Super-fan Mark Jones, from Telford, spent more than £8,000 on tickets to see England play in the World Cup.
He has forked out more than £3,000 for a last-minute trip to Japan, having just returned from watching some of the earlier stages of the competition.
"I would have felt gutted if I had passed up the opportunity to watch them play the final live. It would have ruined the game for me," he said.
He has spent more than £1,500 on the match ticket alone, which he admitted made him feel "a bit sick" but said it would be worth it.
He said: "I had to buy a hospitality ticket so have basically spent £1,500 on a few pints and the game."
Official packages from England Rugby sold out some time ago.