Sure, here’s one of the product pages. The Beta feature for Ajax validation is off, so the only thing you can check is the additional cost not being included.
Simply disable JavaScript, fill out required fields, and make sure you check the “Is This A Rush” checkbox. Once you add it to cart and look at the cart, you’ll see the issue. If you select “1-sided”, “250”, and “NA”, the price should be $53 when the rush checkbox is checked, but will show $33 if you have JavaScript disabled.
Please let me know if you need to know more or if you figured out the issue and will fix this.