Concert sold out — offered privately 'at cost price'

In a fan group someone offers tickets. After payment you receive a PDF that was sold several times — it is rejected at the door. Payment went by transfer or friends & family. Warning signs: Payment without buyer protection requested; Seller pushes because of 'other buyers'; Ticket arrives only as a PDF or screenshot. What to do: Report the payment, save screenshots, file a report and inform the group or platform. Typical loss: 40–500 €.