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.
Selling a dress from the Juicy Couture brand. Size L, new, with a tag. Bought for the summer, lost weight, now it's too big for me in the chest, and in the hips as well. Bought at buzz for 4800, I'll give it away for 3500