Kickstarter doesn't handle multiples well, but we have a couple workarounds:
1. If you want two crates, just add the price of the second crate to your pledge and any applicable shipping.
i.e. 2x Santa's Helper = $65 Pledge + $65 Pledge + $10 Shipping + $10 Shipping = $150 total pledge
2. Sign up for Kickstarter with a different email and make a second pledge that way.