I have the sony dsc f717 and am looking for lenses for it. Are the ebay lenses basically crap? I am just a beginner so I don't really need the best, but would buying these be wasting money? Things like macro lenses are about $40 where as with the lenses straight from sony are about 300 each. If I shouldn’t get them from ebay are there any sites that have good stuff that you can recommend?