It's £6.95 for 50g (You can find it using this link) but totally worth it! So soft and also washable! I used 7 balls for this scarf with 9mm knitting needles. The recommended for this wool is 10mm but I wanted the knit a little more tight. It's a pretty simple scarf- just two purl and knit.
There's lots of videos on YouTube- which is how I learnt. Just type in 'Ribbed Knitting'.