The code am working on is the next one: 
 
............
   @staticmethod
   def default_list_price():
       return 1.0
..............
I know that both fields are Property fields, and that is why my code doesn't work.
I am inventoring all my assets, and I need to have some defaults values on the product.template
   Regards.
       Francisco
The solution was
<data noupdate="1">
        <record model="ir.property" id="property_cost_price">
            <field name="field"
                search="[('model.model', '=', 'product.template'),
                         ('name', '=', 'cost_price')]"/>
            <field name="value">,0</field>
        </record>
</data>
Same for list_price
One more time, thank you!
 Francisco