You will get a lot of mixed comments. For cheap, I think AquaTek (less than $100), Milwuakee (less than $100), and co2art (some less than $100, some more) are going to be your best bets. For something more expensive you can look at co2art dual stage regulator, and also GLA regulators (I think these start around $200). There are probably some bundles also that include co2 tank but I think your best bet to save is look on craigslist, fleabay, and I think beverage factory has them. You can probably also find some reconditioned bottles at a fire extinguisher place. Some people will also say build one, which I did but honestly, it was more of a headache finding every part for the build. Please note that some of the cheaper regulators have been known to not last or leak co2 but there are lots of people that have had good success from when I was doing my research.