Perhaps, this module https://www.odoo.com/apps/modules/8.0/product_supplierinfo_variant/ will help to meet your goals

 Hi,

Follow the below steps and you can achieve your requirements :-

1. Create a product Service Contract

2. Now under VARIANTS on the product form page, create Attribute and Product Attribute Value( Refer Screen shot 1 )

   Attribute                  Product Attribute Value

   TYPE                      Gold,Silver,Bronze

   YEAR                      1Yr, 2 Yr, 3Yr

Screen Shot 1 :- \http://prntscr.com/affd22

3) Now you can check it by clicking on LIST OF VARIANTS( Refer Screen shot 2 )

Screen Shot 2 :-\http://prntscr.com/affchi

4. Hence you can have a single Product with multiple variants and still have unique pricing for each

Hope this helps

 Cheers!!

The extra price is by variante, so you cannot create 2 variante : # year and  grade...

The easy way is to create 1 variant Type:

With 9 values : Gold 1year, Gold 2year, Gold 3year, Silver 1year, ...