Backpacks are usually not cheaper from overseas due to high delivery costs but this one is an exception. A fair bit less than Australian retailers and a full size quality backpack for hiking and travel.
Note that if you never go on multi day hikes, a travel backpack might suit you better, these are optimized for carrying all day and to minimize weight.
To get this price, add a zero foreign transaction fee (28 Degrees, Citibank Plus etc.) credit/debit card and set its currency to pounds (GBP).
VAT gets taken off at checkout.
That backpack weighs 2.8kg. Not for the UL folks.