... you can now do so in one easy step.
http://global.ebay.com/However, just be aware that you're unlikely to get many results from eBay France for a mediaeval seal unless you use the FRENCH term therefore (i.e., sceau médiéval); ditto for German seals (i.e., Siegel, Petschaft, Siegelring if you're looking for a seal ring or signet ring); ditto for Italian seals (i.e., sigillo medievale), etc.