Crochet yarn - where to buy good quality yarn

Wool Warehouse currently has a sale on Drops yarns that contain cotton. Drops Paris is down to 75p (or 85p depending on colour choice). It is an aran weight yarn that is good quality. Others are available, but to get the sale ones search under Drops on the Wool Warehouse website and filter the cotton ones. I don't know how long the sale is on, so do it quickly, as they rotate the discounts.