Hi.  I'm not sure if this is the right place to post this - but your Food theme is flawed ( doesn't work properly )
http://food.grandnode.com/arabica-coffee-beans  ( ignore the "test"  attribute )

Lets assume you have "Product A"  a simple product used to display other simple products and each simple product has it's own price , old price and tiered price
Tiered prices are only displayed if you put them in the "Parent" Simple Product

1) Old price & Tiered price are not displayed
2) If you select one of the radio buttons and add to cart - it adds at full price not using any of the tiered prices

Ideally - this layout should be on a grouped product page:
- but there is no easy way to give the value ( like if you want to display 1kg ) on a grouped product page - unless you do a product specification attribute.  And if you have hundreds of products - then product specifications are not really going to work.

Product attributes don't support old price or tier prices. GrandNode does not have this functionality and never has. Product attributes can be used to create a variants with a price modification, but they are not a product, so they don't have old price or tier price fields. As I said, you can use grouped product with associated simple products and customize the product template to achieve the desired appearance of it. To make is same as product attributes appearance. But you can't treat product attributes in a way that you described.