The Vinery Stud Stakes and Empire Rose Stakes winner for Gai Waterhouse and Adrian Bott got to $2.7 million before being knocked down to Coolmore's Tom Magnier.
She will head to Jerrys Plains in the Hunter Valley after campaigning in Queensland, where she will be a high-profile mating for boom first-season stallion Home Affairs.
"We're delighted to get her, she's a standout mare here and we've got a great crew of clients and investors that have come together and they want to buy the best mares for Home Affairs," Magnier said.
"To get a mare like this is very exciting. There's an old saying, breed them to the best if you want to get the best."
The daughter of Not A Single Doubt and the O'Reilly mare Drinks All Round, who has won $1,344,075 on the track after being bought for $200,000 as a yearling at Magic Millions, attracted an opening bid of $1 million and quickly escalated to more than double that before Magnier proved strongest.
Shout The Bar was offered by Brett and Rachel Howard's Glenesk Thoroughbreds, who were thrilled to play their part in the sale.
"She's a queen, she's certainly the most outstanding mare that we've been privileged to take to an auction, so it's good to see the owners rewarded," Brett Howard said.
"It's a real privilege for myself, Rachel and our team to be entrusted with a mare like that so to get that sort of result for everyone makes for a very fulfilling evening."
Shout The Bar was the banner lot of a sale that saw five horses sell for at least $1 million.
The second highest-priced lot of the night went through immediately after Shout The Bar with Hilldene Farm and James Bester paying $1.6 million for Sia (Fastnet Rock), a $1.1 million yearling who is a sister to Lake Geneva, Ennis Hill and Acrobat who is in-foal to Snitzel.
Michael Christian and Sheamus Mills went to $1.45m for Ellicazoom (Testa Rossa), a daughter of Group 1 winner Ellicorsam who is in-foal to I Am Invincible, Mill Park paid $1.2m for Quantum Mechanic (Deep Field) and Coolmore Classic winner Daysee Doom (Domesday), who is in-foal to Wootton Bassett, sold to Widden Stud and David Redvers for $1.1m.
All up, the 84 mares offered at the black-tie event at Warwick Farm's Riverside complex grossed $32,605,000 at an average of $472,536.