The last Bioshock auctioned on ebay was 100% mint, included the outer envelope and promo and sold for 430 euro.
http://www.ebay.co.uk/itm/1813103110...84.m1423.l2649 There seller has 10 percent fees, leaving about 390, minus paypal fees about 375.
Since yours is little damaged and no outer envelope (i believe you were able to include promo), i keep my bid of 300
