Previously, the Cart Transform API allowed percentage based adjustments to the cost of a bundle when using
expand operations. The (weight price algorithm) (http://shopify.dev/docs/api/functions/reference/cart-transform/developer-preview#/weight-
price-algorithm) would then allocate the bundle price to its component lines based on the weight of each component line (unit price * quantity).
With this release,
expand operations will also allow you to set fixed prices on each component of the bundle, resulting in a bundle price that is the sum of each component. Additionally, the
expand operation will now allow you to define a custom title and image for each parent line item.
This gives you more control over bundle pricing and enables bundles to be used for add-on products.
More information can be found in the Cart Transform API developer preview documentation.