Sven's Barter Store is a store that works quite a bit differently from most of the other stores in CE. Sven's will accept many of the items that end up in the "Misc" section of your Ship's Store and give you a set amount of Barter Points for them.
Barter Points can be exchanged for items that normally require a bit of effort and/or luck to obtain. A good example of this is being able to trade Barter Points for Commercial and Industrial Extractors, which can only be otherwise obtained through the process of crafting or via the Player Market/directly trading with another player.