Katadyn Combi =$139.95
.2 micron filter 13000 gallons plus replaceable carbon granules for pesticides,chemicals, etc..

MSR MiniWorks EX = $66.95
.2 micron filter 2,000 liters (528 gallons) plus carbon
Replacement filter is $39.95 for every 528 gallons

http://www.geardirect.com/browse.cfm/4,2164.html

The Combi is still the best for the buck system in the long run.

13000 gallons / 528 gallons = 24.62 filters

You would go through 25 filters at a cost of $999 total (25 X 39.95) before you would change 1 filter on the combi.