I bought a generator many years ago and it is still working fine. That is what I drink and use for most things. However, if I have to buy some to give away, or just to have extra dropper bottles, I usually use Puritan Pride. I catch their sales, and right now I think they have a buy one get two free sale until the end of the month. I think it is 5 ppm. You can also check the net and get some good deals on 8 ounces, or used to be able to.
I have found that low ppms are just as good, if not better for everything I have ever tried it for, so I don't waste money on high ppms.
A generator is great if you find you are going to be using it a lot, for example, tend to candida. Or have family that use it too.