When you registered to bid you confirmed the following:
I agree that I have read and understood Bonhams' conditions of sale and I wish to be bound by them, and I agree to pay the buyer's premium and any other charges mentioned in the notice to bidders. I understand that this affects my legal rights.
For all Sales categories excluding Motor Cars and Motorcycles:
Buyer's Premium Rates
22% on the Hammer Price
GST at the current rate of 10% will be added to the Buyer's Premium and charges.