These filters are really pricey, but better than toting home gallons of bottled water.
They are 20% off this week at Longs, and there is a rebate for $3, limit 2. This brings the price down from $18 regular to about $12 or so... you can get either the single packs or the multiples, but it was cheaper (per unit) to get the singles. I got one, debating on going back to get one more just because I can and I haven't found them cheaper elsewhere.