$40 for distilled/deionized water? You got ripped.

should have been at most $4-5 bucks.

I agree with RF about not running water long term. Use of distilled water only is to get you to a place where you can do the flush safely. Use of water with no anticorrosives in place will lead to engine damage. You only have a day or two if running on distilled water only until you flush. Follow my sig for the link in flushing coolants.
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Stalag;___________Just for Rizzo I am posting this in my sig. Coolants
2001 Lincoln Town Car Cartier L, 1997 Mercury Grand Marquis (extinct)
On my LTC the following mods/upgrades were added. Heinous motorsport control arms, Command Automotive SD-1 rotors (these rotors can no longer be obtained), Calipers by Goldlinebrakes.com in silver with Hawk HPS pads (now running Ford OEM), MSD COP's. MZT is also applied with programming from BOC. j-mod is now done. Final rebuild of transmission done by Gearstar.