Emma claims her dog to be worth 10,000 francs; this is equivalent to over 60,000 euros in modern terms, a highly unlikely price for any dog. Boudu's five francs is equivalent to about 3 euros in modern money.
edit: according to your math it would be 6,000 not 60,000.
Edit: Emma actually claims the dog is worth 100,000 francs, so at 5:3 60,000 Euros is right.