Data attributes and tag-based class names

This suggestion adds 3 data attributes: variants, alpha and price. These can be used to produce client-side jQuery sorting and filtering effects.

Along-side this is an expansion of the product CSS classes to include all assigned tags, prefixed with "tag-"

This is useful for applying CSS effects to custom groups of products. You could indicate brands with logos or subtle colour variations and more- it could also be used to provide client-side on-page tag filtering.