One of the biggest issues I have seen with scripts is that it is really easy to give discounts based on line item value, but calculating the cart value, and applying logic based on that is causing a lot of people issues. Here is a REALLY easy way to solve for this and I will give two examples.

1. $X Off if Cart is over $Y

This will give the customer a discount of $5 if the cart is over $30.

1. Variable discount depending on cart value

This will give the customer a discount of $5 if the cart is over $50 OR will give them $10 off if the cart is over $100.

As always, let me know if there are any questions in the comments.