I was looking on B&H and I saw that they also sell used lenses. I'd like to save some money, so I was thinking about buying a used lens. Maybe this one:http://www.bhphotovideo.com/c/product/800533968-USE/Canon_9517A002_EF_S_17_85mm_f_4_5_6_IS.html For almost $100 less than a new lens, would you recommend buying used, or buying new? Also, the new lens includes the lens caps, but this used one does not say anything about them. Should I assume that it does not come with them? If anyone has bought used lenses through B&H, I'd like to know if you would recommend it or not.