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: 1. IKEA navlinge lamp on a powerful clip. 220 lumens, 2700 kelvins. 200 dinars. Sold 2. Silent ball, in case of anxious neighbors. 200 din. Sold 3. Children's armbands for the pool. 200 din