I have the Panasonic PJ-A3AH which cost about $799 when I bought it 6 years ago. It works very well IF your tap water doesn't suck so hard that even the filters don't work.
I lived in another area the first 5 years I had it and it was great. Very good alkaline readings and the water tasted great. Recently I moved into an area I thought was nice, but found out after I moved into it, was really terrible. The quality of the tap water is so bad that the Panasonic water filter doesn't work nearly as well. The water is much more acid. I still use it for making tea and cooking, but I drink bottled water for the time being. I'm not sure if it's the quality of the tap water from the municipality or if it's a problem with the pipes in the home I'm renting. I'm moving out of this place as soon as possible.
So, it can be worth the money if your water is decent enough in the first place.