Yeah I wouldn't chance it. I remember someone on the forums purchasing a supposed early release playbook on ebay and finding out it was an old development model.
As I said, it's a mistake. The guy just clicked the wrong box on ebay. If you try to sell on ebay, and you tell them that you're selling a Blackberry PB, they'll in effect, ask you which model (including models that don;t exist, yet- see first pic) If you click the wrong item, you'll get an incorrect description (see second pic). This may be further indication that a 4G is on the way- soon.