Around the World in Eighty Days · Jules Verne, 1872
How much did Phileas Fogg bet?
£20,000
Half his fortune, staked at the Reform Club. The other half paid for the trip, and he spent about £19,000 of it.
From the book
At the Reform Club, Fogg says he has twenty thousand pounds at Baring Brothers and will bet all of it that he can go round the world in eighty days. That is half of what he owns. The other half goes into his carpet bag as banknotes, to pay for the trip.
He spends freely. Two thousand pounds for the elephant, two thousand for bail in Calcutta, money for a pilot boat, a sledge, and finally the Henrietta, which he buys and burns. By the end, Verne says, he has spent about nineteen thousand.
So he wins the twenty thousand, but the profit is small. Fogg doesn't mind: he did it for the challenge. He shares the thousand pounds left between Passepartout and Fix, and only takes off Passepartout's share the cost of the gas he left burning at home for 1,920 hours.
See the bet at the Reform Club