Calculating Percentage on Excel cells

I am using Microsoft Excel to calculate the percentage options of the following: For items that cost $30 or less, the fee is 30% and minimum of $5.
For items that cost more than $30 but less than $50, the fee is %20 and a minimum of $6. For items that cost more than $50, the fee is 15% and a minimum of $10. I need a formula that I can use for both the cell for the
(1) amount and the cell for the
(2) result, without using a third cell for the percentage.
Can anyone help me on this?
