If you can find it on ebay, it should be fine. I would make sure it's from a reputable supplier though as the kits do have a shelf life and if you happen to get one that's very old, it might not work properly, especially the nitrate kit. They are usually good for about 3 years from the date of manufacture which, oddly enough, appears to not be stamped on the outside of the box but only on the inividual bottles.