Comment Continuous Re-inking System (Score 3, Interesting) 439
That's what you want my friend if you want the lowest cost per page. Quite a few people are running these in Cannon S series and some of the middle tier Epsons for commercial use. More Info here http://www.weink.com/ecart/crs.htm although I'm sure there are other manufacturers as well.
The inks in the kits are rated for 20 years under glass. I've been using them myself (not the CRS, but the same inks) for about 7 months now and I'm happy as a pig in slop.