I bought some of these last year. Really good for the price.
http://www.ebay.co.uk/itm/0-5-1-0-1-...item54131faabd
You get 4 of each: 0.5/1.0/1.5/2.0/2.5/3.0/3.5/4.0mm
if you check their shop, they also do them in Purple, Black, Yellow and maybe other colours too.