RubyToogood
RubyTwobikes
I am convinced but I must be disciplined and use up the yarn I have first and then buy some more for the cardy.... I will be good, I will!
It takes very little wool though, it took me nearly half what it would take to make any other jumper. If you were careful and shopped around you could probably do it really cheaply. Frinstance, I reckon that if you were a medium and went for New Lanark aran, you would only need 6 balls: total £17 plus P+P.
http://newlanarkshop.co.uk/shop.php?view=category&category=91