I got this one
http://www.peterchild.co.uk/pyroinfo/pylist.htm
you can pick up rougher pyrography pens in hobbycraft for about £40. they arent as good but youll learn if you enjoy it or not with a cheap one
I must say the fire pen is the best thing I ever bought. Id encourage everybody to buy one for the enjoyment its brought me, but don't because I wont get any more commissions!
I've seen this one on the Axminster site Lindz, do you reckon it'll be up to much for £15 ?