This Samsung Plus 32GB class 10 microSD card is currently going for £17.48 (Low Price Memory), £17.48 (Memory Card Zoo) or £17.49 (Locoisle) at Amazon. Nice.
Locoisle is looking good, with a 99% positive rating in the past 12 months, and 15,768 ratings in total.
Delivery included in prices.
(Thanks to mgb20 at HUKD)