I am going to purchase a sigma 10-20 from adorama and it comes with a filter, lens leash, and cleaning kit for 480 do you guys think this is a good deal. I guess my question is if i get a bad copy as seems to happen sometime with this lens is adorama good about taking things back or exchanging them out. Or do you deal directly with sigma at that point. I amno professional and I have not purchased online in the past so thanks for your experiences.