Ticket : Different price depending on attribute #3NUF7R-7LA

I tried our extensions for a new ecommerce site.
In Catalog I found that I can enter a different price for quantity (tiered pricing).
Is it possible to have a different price for an item's attribute ?
For example : I sell a jam that costing 5EUR if the weight is 220g or 7EUR if the weight is 340g .
So I would like to have one item with the choice of the packaging and the price changes depending on the package chosen .
Is it possible or I must have more different items ?
Thank you.