We bought a memory foam topper (with its own cotton zip round cover) and it made our already comfy mattress just heaven! Dh bought it (he's asleep so can't ask where from or price and I can't remember at the mo). Dh is v thrifty so it won't have been v ££££. My brother bought a ££££ tempur mattress and he and my sil hated it. He's a tall, muscle bound man and apparently would feel like he was sat in a bucket each night because it dipped in a v shape when he was in it and sil rolled into him.