RDF 1.1 - Skolem IRI

Good morning,
 
We use http://www.w3.org/TR/swbp-n-aryRelations/#useCase3 throughout.
 
Are you saying that Purchase_1  in the shown code:
:Purchase_1
      a       :Purchase ;
      :has_buyer :John ;
      :has_object :Lenny_The_Lion ;
      :has_purpose :Birthday_Gift ;

      :has_amount 15 ;
      :has_seller :books.example.com .
shall have a Skolem IRI? If so, why for Pete's sake?
 
And if so, must we really waste storage space by adding .well-known/genid/
to those IRI's?
 
Regards,
Hans
 
OntoConsult,
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