Not being on Medicare, and not having medical insurance, I've been pretty much on my own in regards to INR management.
For many people, using Alere or Philips is a viable (though expensive to the insurer and possibly also to the insured) option. They'll send you the meter and supplies. They may nag you for results that they don't receive when they want to receive them (I'm sure about this), and they'll report your INR to the doctor or clinic that is managing your INR. Some on this forum have had serious billing issues with one or more of these companies.
For myself, I've gone through a few different machines - bought on eBay (with one exception). I started with a ProTime and later moved to an InRatio. (I'm now, perhaps, getting a lab quality meter that mere mortals aren't supposed to come within ten feet of, but having had a stroke, my life is a bit more important to me than making some vendor happy). I would be happy to try a CoaguChekXS, once I can get one affordably.
You should be able to get new meters on eBay -- with warranty -- from medical equipment vendors that sell on eBay. You can get meters that were 'retired' or 'upgraded' by clinics or hospitals and replaced with newer technologies. These meters are probably just fine - they worked for the clinics or hospitals that 'upgraded,' and should work for you. The move from performing possibly dozens of tests a day at a clinic to performing a test a week should be fine for the meter. I didn't fear eBay for these purchases. I still don't
DO NOT BUY A COAGUCHEK S - or any Coaguchek other than the XS - the others have been discontinued and there are no strips for them that are easily available. (There may be some, somewhere, overseas).
As N Jean said, you WILL love the freedom of home testing.
(One other thing -- you may find that your meter varies fairly consistently from a lab's results. See if you can compare your meter's results to your lab's. My meters (both the InRatio and InRatio 2) are fairly consistently .4 - .6 above the lab results - I wish I had known this in April. Once you know your meter, I recommend that you test weekly (I do). Just make the simple adjustment to bring your meter results close to where the lab results would be. In my case, if my InRatio or InRatio2 gives me anything between 3.0 and 4.0, I believe that I'm pretty close to my 2.5-3.5 range. If you get a crazy result (above 4.5 or below 1.5, retest and, possibly, go to a lab for confirmation)