Next Day Delivery option - how best to apply?
We want to add an option for the customer to be able to upgrade their postage to next day delivery. Is this best done by adding Next Day Delivery as a static item with its own Add to Cart button?
My confusion over this is because my client wants to charge two different amounts for Next Day Delivery based on the TotalWeight but that would mean adding two different Add to Cart buttons, wouldn't it?
Could I drive the price of the Next Day Delivery static product by the TotalWeight value, like and IF/ELSE statement?
How would that look in the Add to Cart button section above the header?
Thank you.
NJ


Is the best way to achieve this to offer three radio buttons on the checkout page and then have the Shipping rules, in the Shipping tab, respond to which sessions are made live by the users selection from the radio buttons? 
