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.
Mattress protector 160x200 IKEA GRUSNARV, water-repellent - 500 din. Blanket 200x200 IKEA SÄFFEROT, thin and light, but surprisingly warm - 500 din. After washing. Together for 900 din. Palilula, near the botanical garden