Billy?

Yes Billy is definitely considered rare, because he was only made for one year, but what really drives up his price is his condition. The large size of the side stickers, and possibly poor quality of the paper stock causes most used ones to generally have dog eared stickers (same as Whiff), and also, his orange colored stickers are prone to fading too. To find a used one without sticker damage is very rare. That's why a pristine bnib demands such a premium.
They come up on eBay maybe only once month.