How much money do you expect to get by selling it on eBay? Personally, I'd crack it open and remove the battery for recycling (plenty of instructional vids on YouTube for all models of iPhone). I'd maybe sell the screen assembly if you can get some money for it, but smash the motherboard and dispose of the pieces in two locations (also recycling, there are toxic materials in many modern electronics that we don't want in our landfills and groundwater!)