If anyone else has similar tasks – we’ve just released new plugin v2.2.1, where we have:
1. added [product_attr] shortcode, which would be the correct way of retrieving the product’s attributes, e.g.:
[product_attr attribute="number-of-prints"]
You can also get product attribute’s value as suggested earlier by:
[product_meta key="attribute_pa_number-of-prints"]
However it seems that this way only works for variations, but not for simple type product’s attributes, while [product_attr] shortcode works for all types of products.
2. added convert_to_numeric attribute to the [product_meta] shortcode (attribute defaults to yes).