Just noticed Argos are doing a few 6 Piece Towel Bale sets on Buy One Get One Free. They seem to get decent reviews and two sets of towels for £6.99 can't be bad! Ordered 4 sets there for myself. Looks like there are 3 colours available - Slate, White and Light Blue.
Slate = http://www.argos.co.uk/static/Product/partNumber/8280949/Trail/searchtext%3ETOWEL BALE.htm
White = http://www.argos.co.uk/static/Product/partNumber/8280688/Trail/searchtext%3ETOWEL BALE.htm
Light Blue = http://www.argos.co.uk/static/Product/partNumber/8281137/Trail/searchtext%3ETOWEL BALE.htm