Honestly? Probably either eBay or Craigslist - for used ones...you can find them there all the time, and the Volcano is such a well-made product that you can trust even used ones will still be working - plus they're hand-made by German craftsmen and we all know how good German engineering is (yes, I'm part German, and my Grandfather was an engineer). The best prices you're going to get from a mail order shop will be in the $500-$600 range most likely - also be sure that you're getting a full kit, the valve system is a separate box from the Volcano itself - and sometimes sites will hide this to make their Volcano look cheaper - then you realize you still have to spend about $100 on a valve set.