Tier Pricing

I believe the answer to this question is no, but I thought I would ask.  Is it possible for the tier pricing to calculate the quantity discount based upon a $ off or a % off?  For example, a Widget costs $25 US.  Can I setup a tier pricing structure like this:

Qty 1 Discount = 0
Qty 5 Discount = -$2 each
Qty 10 Discount = -$4 each

NopCommerce would calculate the quantity discount based upon the tier pricing levels based upon a $ off the original price.  This allow the store owner to made a single price adjustment as the cost of the widget goes up and down vs. having to update the product price and the tier pricing as well.  

Please let me know if this is possible.

Thanks

I think its not possible without changing the core

I am not sure how but may be you can do it by customizing it or by creating some discount rule that check the tireprices qty and apply discount on it