Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - General D:OS Special DLC

I thought you may have been talking about something with BD on Steam.

The DLC items in the boxed version of the anthology (see here for a description) were actually only added at the request of one of the retail distributors. See a reply to a comment in the blog post Hatching the Anthology.
FWIW, the DLC item in D:OS 'only' allows you to increase equipment's value by 10%, which may come in handy early in the game, but historically gold hasn't been terribly hard to come by in Divinity games. The items for D:DC (in the anthology and Chinese new year promo) seem to be just cosmetic.