This deal from Wowcher
From £119 for a Bradbury pocket sprung memory foam mattress from Desire Beds
Mattress: Get a pocket sprung mattress with a quilted cover and ribbon stitched border. Depth: Approximately 30cm deep with a layer of next generation memory foam which contours to your body shape. Inners: Individually nested pocket springs offering semi orthopaedic support. Firmness: Medium firmness – perfect for those who like to sleep on their side. Properties: Hypo-allergenic filling and properties with anti-dust mite features. Sizes: Choose from six sizes (see pricing below).