Have something unique?

Hi all. Casual LEGO user here. Someone I know used to work for LEGO and had some rare LEGOS given to them. Unfortunately, they did not really understand collectibles being potentially being value. No clue where to start on this due to its nature of being unique but box opened. LEGOS and instruction booklet are still in the original plastic wrapping. The other unique part, its serial #0000. Star Wars (unfortunately not a Star Wars fan) Would eBay be the best place to sell this? Auctionhouse....