How do you want the charges to be made?

If the different prices are based on Item count then clone Item Rate item shipping module ...

If the different prices are based on Weight then there are several modules, Per Unit perweightunit being one of them ...

If the different prices are based on a Flat Rate, then colone the Flat Rate flat shipping module ...

A search on:
clone flat
clone item

would give you the basic idea of how to do this ...