Quantity-Based shipping for USPS

[wcsconcierge]

Hello, I need to implement quantity-based shipping for USPS First Class.  There is a base rate of $5.50 and an added $1.50 per item shipped.  How do I implement that? I have already specified the number of items in each Kit.   Relatively new to virtuemart.  Thanks in advance.

Clear as mud? Check out the bookstore: http://www.devimg.com/avenue/