The Big Wallet is a recurring Wallet in The Legend of Zelda series. Once Link receives the Big Wallet, he stores additional Rupees than he previously could.
The Minish Cap
In The Minish Cap, Link purchases the Big Wallet from Stockwell's Shop for 80 rupees. It is the first Wallet upgrade and stores up to 300 Rupees, 201 more than Link's original wallet.
In Twilight Princess, the Big Wallet is given to Link by Agitha after he gives her one of the 24 Golden Bugs. It stores up to 600 Rupees, or 1,000 Rupees in the HD version. It is the first Wallet upgrade. Agitha later gives Link the Giant Wallet if he gets her all 24 Golden Bugs.
In Skyward Sword, the Big Wallet is given to Link by Batreaux after Link has given him 30 Gratitude Crystals. It stores up to 1,000 Rupees, which is 500 more than the previous Medium Wallet could hold, and is more than enough to purchase most items in the game. It is the third Wallet in Skyward Sword.
Big Wallet icon from The Minish Cap
Art of the Big Wallet from Twilight Princess
Icon of the Big Wallet from Twilight Princess HD
The Big Wallet from Skyward Sword