Before you commit to spending a lot on any water purifier, consider checking what Hulda /Clark's newer books and her website say about recontamination from the filters and effects of same. She warns that certain substances CANNOT be adequately filtered out of our water, and MUST be avoided. Has info on both lab and home testing for same. Also some good info there regarding what substances to avoid or cleanse from your system in order to discourage candida, breakdown of detoxification pathways, chronic ill health, etc.
Be warned, though. This is NOT easy info to assimilate and use. Will take considerable time and effort. I'm doing this now because the more commonly known and easier options havn't worked for me. Wish I had had this info 20 years ago when I first became disabled!
Whatever you try, I wish you the best. Should you come across a filter system that is affordable and can filter wheel bearing grease residue out of whater to the point that Clark's synchrometer cannot test for it, please let me know. Thanks.