BMATTICE

Well, I had all of the parts available. But I can give you a quick run down.Water bladder $12-15Sewing kit $1Backpack $12Velcro strap $3Carabiner - $1.50So, in total including the water bladder (which you would need for some water packs anyway) you're looking at $25-$30. That's great considering a typical water pack costs at least $80 and can be as expensive as $150. But I used stuff I had laying about the house and converted an old backpack of mine. So it can be even cheaper.