The AR-7 (now by Henry) prices in at $250. I'd love to have one of those if I could afford it. I'd also love to have one of those $250 Katadyn reusable pocket filters, can't afford that either. For water purification i'll be packing one of those flimsy bottles of water you can get for $1.50. The idea being that after drinking the water, I'll put the cap back on, poke a hole in it then cut off the bottom and fill it with layers of sand and charcoal and keep reusing it over and over to filter my water before purifying it with Iodine or boiling it. I'll of coure be replacing the sand and charcoal from time to time as I go.