This Mid Back Black Leather-Faced Manager's Chair is available at argos for £29.99, for reservation and collect at store, not for home delivery. It's a very good price for a basic leather chair. The worst thing about it is that it comes flat pack and you have to spend half a day figuring out how to put it together! Thanks go to Ducky for spotting this one.
Details: Black leather-faced chair with PVC sides and back. Medium back with back tilt tension mechanism. Gas lift seat height adjustable from 42 to 52cm. Seat size 50 x 48cm. Size (H)94-104, (W)63.5, (D)68.5cm. Total weight 12kg, supplied in 1 box. Minimal assembly required. Packed flat for home assembly.