According to § 25a differenzbesteuert which VAT is deductible! This is the final price plus. Shipping!

*** Vintage means that the watch is at least 20 years old. The watch is fully functional, but in an age-appropriate condition. In general, we assume no liability for the waterproofing of vintage watches.

**** Warranty for consumers for used:

Your warranty claims due to defects in used goods expire one year after delivery of the goods sold to you. Exceptions to this rule are claims for damages, claims for defects that we fraudulently concealed, and claims from a guarantee that we have applied to the condition of the goods. For these excluded claims the gestzlichen limitation periods.