Emilyandlily via eBay offers this 3-Liter Hydration Pack Backpack in Black for $9.99 with free shipping. That's tied with our mention from a week ago and the lowest total price we've seen. (It's also $2 below the best price we could find for a comparable hydration pack elsewhere.) It features 600-denier nylon construction and adjustable shoulder straps and chest belt.
These tips and tools can help you recoup thousands of dollars if the unthinkable happens.