iPhone 11 smart case

[extraT]

I’m travelling Munich - Heathrow on Saturday, spending the week in London. I’m looking to buy an iphone 11 smart batter case. Any tips on where to pick one up? Ideally I don’t want to pay the 130£ So I’m happy with a premium reseller as well as original (if it can be had for less than 130). My Google-fu is letting me down. Any tips or leads?

Cheers

ET