Well, first off, fixed price is pretty much expensive since you set off a price that you can't auction off, no changes whatsoever in this type of scenario. Other people may coin it as "end price." The store price is going through the competitive approach as this is the "bidding" price that will help you survive in the market.
However, you may want to check this thread out as they also discuss what should be suitable for you. You might be surprised however that you can actually deal with both :)Link hidden: Login to view
Hope this helps!