I bet someone said he'd undersold it and offered him £20 or something, and he hoped you were after the software.
He's legally obliged to send it to you now, though, as he accepted payment for the goods - if he doesn't send it he'll probably get kicked off eBay if they find he sold it elsewhere.
In reality what he'll probably do is claim it got "broken" and "thrown out" and offer a partial refund, in which case by law you can send what you got back and get _all_ your money back.