For thorns, your cheapest option is Edge runeword. Level 15 thorns on it, and all you need is a 3os bow + tir tal amn.

You can find all the info you need on the wiki for uniques and runewords we have edited, and any runewords that arent on the wiki are as they are in regular d2, and you can find all that info here: http://classic.battle.net/diablo2exp...unewords.shtml