I guess 611 EUR goes a long way in Colombia/Venezuela... Maybe from his perspective, it's worth skimming a European who doesn't have her wits about her.
How 550 EUR from the first post turned into 611 EUR? And can you clarify if this money has already been sent to the alleged seller and what was used as a means of payment? I don't understand why you agreed to the transaction outside of exchange, and why you pay for something in advance (if I understood correctly that the money is already lost)?