Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.
For sale: Robot vacuum cleaner with attachments for dry and wet cleaning mamibot exvac880. New brushes and filters - 6k. Xiaomi air purifier 4 pro air purifier. Excellent condition, filter life 16% (better to replace) - 18k. Belgrade, Zvezdara
