For the price of Pelicans or Otters, you're getting a lot, in the way of waterproofing and durability.
If you wanted to spend a couple dollars less, you could go to an art supply or hardware store (or even better, the Container Store if you have one near you), and see what they have. But I highly recommend forking out a couple extra dollars and getting Pelican or Otter - cause "good and cheap" don't really go together in this case, IMHO. :shrug:
john