"Thank you so much to everyone that placed a bid & a huge Thank you/ congrats to the successful bidder - you have blown me away with your generosity and this was way beyond my expectations," he tweeted.
Thankyou so much to everyone that placed a bid & a huge Thankyou / congrats to the successful bidder - you have blown me away with your generosity and this was way beyond my expectations ! The money will go direct to the Red Cross bushfire appeal. Thankyou, Thankyou, Thankyou ❤️ pic.twitter.com/vyVcA7NfGs
— Shane Warne (@ShaneWarne) January 9, 2020
"The money will go direct to the Red Cross bushfire appeal. Thank you, Thank you, Thank you." The item comes with an autographed certificate of authenticity from Warne. The identity of the successful bidder not immediately known.
The "baggy green" is awarded to Australian players when they make their Test debut and is worn as a badge of pride when they are on the field.
Warne decided to put the cap up for auction on Monday to help those who have suffered in the catastrophic fires that have devastated parts of the country and left at least 26 people dead and almost 2,000 homes destroyed.
"The horrific bushfires in Australia have left us all in disbelief. The impact these devastating fires are having on so many people is unthinkable and has touched us all," he said then on Instagram.
"Everyone is in this together and we continue to find ways to contribute and help on a daily basis." Fellow cricketers Chris Lynn, Glenn Maxwell and D'Arcy Short have pledged to donate Aus$250 for every six they smash during the ongoing Big Bash League Twenty20 tournament.
Top tennis players have also got involved, with world number one Ashleigh Barty donating her winnings from this week's Brisbane International
to the Red Cross, although she was knocked out at the first hurdle.
Fellow Australian Nick Kyrgios, among others, has promised Aus$200 for each ace he serves during the home summer of tennis.
A "Rally for Relief" exhibition match at Rod Laver Arena in Melbourne featuring Roger Federer and Serena Williams is due to take place on January 15 ahead of the Australian Open to raise further funds.