Bought a 4 pack in Home Bargains today for Just 99p .
They the twin tip ones , so one side is fine the other is ultra fine.
Black, Red, Green , and Blue in the packhttp://www.sharpie.com/enUS/Product/Sharpie_Twin_Tip_Permanent_Marker.html
there's a link to the sharpie web site if you want to know more about them apparently they write on anything
Also bought some nice embossed wrapping paper and tags that from woolies originally and was sold at £2.49 only 19p in Home Bargains