Ooo Wool Porn!

Went to John Lewis and drooled over the knitting wool. This is Noro yarn, a lusciously dyed, Japanese wool that is VERY expensive - £16 for 100 gms.
The only thing I could afford to buy was the pattern book, so need to find a substitute yarn that looks similar (attractiveness of the patterns depends on the variegated colours in the wool) but which is much, much cheaper.