Bought the cape (Neca), helmet (Neca), greaves (Bronze Armory), vambraces (Bronze Armory) and sandals on ebay. Had the helmet, greaves and vambraces padded so it would fit me better.

Went to Dutch medieval/fantasy/gothic/pagan fair Castlefest 2008.

2012 edit: looking back on the costume I had a lot of fun on the day when I wore it, but the pictures make me cringe every time I see them since I really lack the physique to portray a Spartan. And I only got fatter since then. The beard is nice though :)