New to Ozonated Water

Want to buy a machine. I found this link through search, I'm on a budget, so is something along these lines the right tool for my situation? Which of these have you guys used to recommend?

http://shop.ebay.com/?_from=R40&_trksid=p3907.m38.l1311&_nkw=water+ozonator&_...

Particularly, have any used this one:
http://cgi.ebay.com/600-mg-h-Ozone-Generator-Air-Water-Oil-Ozonator-Ozon_W0QQ...



According to the info on this page, a home-grade should cost $300?:

http://www.cancertutor.com/Cancer02/BobBeck-OZ.html


So are you not getting the quality with one of these 50-60 dollar units? Is the ultimate difference speed of ozonation, or what? Lifespan?

How long would it take a unit like this to ozonate half a gallon of water? Do you need to add salt to this water to keep balance? Any reference links to good comprehensive information on these matters would be appreciated...Thanks very much..