For sale on EBay and marked as a "Rare example of gunuine (sic) 17th century bookplate, probably from Germany, exceptionally rare in this condition, slightly age stained on reverse", try as I might I can't see what it is that might be so rare as to demand a price of £129.99. Admittedly, if it is a genuine 17th century bookplate it will have a certain rarity but 130 quid?
I look forward to seeing if it sells!