In my opinion, it sounds too good to be true.
Here's what I would guess: The seller might have stolen the computer. He/she ships it to you, without an advance payment, because there is nothing for the seller to lose if you don't follow-through with the money (if the machine was stolen anyway). If you pay, then the seller made a profit.
Would a reputable seller allow you to pay afterwards? I don't think so. There are many clever scams in the world, and it sounds like you are in the middle of one. It's hard to see when you are so excited about getting such a product.
It just sounds very, very fishy to me. My opinion is that it must be stolen.
Here's what I would guess: The seller might have stolen the computer. He/she ships it to you, without an advance payment, because there is nothing for the seller to lose if you don't follow-through with the money (if the machine was stolen anyway). If you pay, then the seller made a profit.
Would a reputable seller allow you to pay afterwards? I don't think so. There are many clever scams in the world, and it sounds like you are in the middle of one. It's hard to see when you are so excited about getting such a product.
It just sounds very, very fishy to me. My opinion is that it must be stolen.