My situation may be slightly different - and in the past, unfortunately, some people have found it rather controversial.
I don't have insurance. I'm not on medicare. All my ACT is done by me, out of pocket.
About 20 months ago, I was able to get a ProTime meter on eBay for a minimal amount of money. There were a few reasons I got it -- the primary was the price of the meter (it was much less than the CoaguChek or the InRatio meters). I was shopping for one, off and on, for a while. Aside from price, I liked the fact that the ProTime had built in quality controls on the strips. The CoaguChek S didn't, and both it and the InRatio were way beyond my price range.
The ProTime 3 channel strips were about $5 each - a doctor ordered them for me and got the medical professional's price. These strips come with a lancet and blood collection device, so the cost of lancets was irrelevant.
Since then, I replaced my ProTime (which a hospital lab test showed was extremely accurate), with the newer ProTime model - the ProTime3 (which used the same strips, but is a little nicer unit, and which I got for about $50), and later got a CoaguChek S (for $40) because a lot of people on the forum indicated their preference for this meter. (The S was new, but I haven't been all too happy with it -- even though it takes much less blood than the ProTime, I've wasted a lot of strips because it wasn't easy for me to accurately place the drop of blood on the strip). The cost for these strips was also about $5.
For the CoaguChek S, I tried a lancing device that was included in blood glucose test kit that I bought for just a few dollars, and primarily for the lancing device - and some 21 gauge lancets that I bought for pennies apiece. I also tried some single use lancing devices designed to get big drops - these were about 20 cents each.
Warfarin was the same price that others quoted - $10 for 90 10 mg and $10 for 90 4 mg -- my daily dose is usually 7 mg, so 1/2 of each pill is what I take, and it costs $10 for 90 days.
If you don't count the cost of the meters, bought on eBay from reputable sellers, and consider two tests a month (if I don't waste any CoaguChek PT strips), then the total cost per month for two tests and 30 doses of warfarin is about $13.
If I had insurance, the answer may have been a bit different....