This image demonstrates three features of Drupal Commerce:

1) Product fields are pulled into the node that displays them via the Product Reference field.

2) The Add to Cart form display formatter for product reference fields displays attribute selection using field data from the referenced products; it only displays options that actually exist on products referenced by the field.

3) As options are selected on the form, the product fields displayed on the page are updated to reflect the currently selected product and the options on the form update to show newly available options, allowing for attribute dependencies to any depth in their order of appearance on the form.

A picture is worth a thousand words, but a forthcoming video and live demo of this behavior will do much more to convince you of how cool this is. Three cheers for Drupal 7!  ; )

You can enable as many currencies as you want and use them to set your base product prices. Currencies use a default price format that can be altered via a hook. They can also specify whether or not prices have decimals (i.e. the price of Product Four) and how they should round (i.e. CHF rounds to the nearest .05).