Support for alternative price lists in combination with discounts

[gadgetto]

Need to create a special field type which offers alternate price list creation.

Snipcart will look at the product definition (anchor output) to see if there is a price matching the alternate price list.

For instance, if you want to offer special prices to your VIP customers, you could add a discount that uses an alternate price list named "vip". In your product definition, you would have to add: data-item-price-vip="100.00"

Once the discount is applied, Snipcart will change the item price in the cart to the one defined by the alternate price list