This was posted 5 days ago. Also its an amex deal not really a Google store deal.
Well OP, thanks to @MentalFloss ' ingenuity a new deal has emerged, potentially much better value
I wanted a new phone and I upgraded to a Pixel 3 XL Black with 64gb for £20 a month. I kept my sim plan and had a bit of bargaining with the Vodafone upgrade team and got the phone for £20 / month for 2 years.
Can you elaborate a bit more?
I got it for £20 pound a month from Vodafone.. if anyone is interested