Excel 2007 : eBay comission code, various percentages...

Hello. This is my first time here so please be gentle.
I have this spreadsheet that I use to calculate my sales price for my items on eBay.
In order to calculate eBays comissions, I have to imput manually the costs into the fields.
I want to do this atomaticly. It is a rather confusing methode eBay uses.
I have 0 to 29.99 comission fee is 5.25%, 30 to 99.99 comission fee is 3%, 100 to 199.99 comission fee is 2.5%, from 200 to 299.99 comission fee is 2% and from 300 to 599.99 comission fee is 1.5%.
As we can see this is a tad complicated.
What I am doing is uppon finding my selling price for an item, I then add these numbers manually.
As an example;
Item price is 215.31, I then do this;
29.99
69.99
99.99
15.34
the percentages are found automatacly and then added all together.
What I need is to creat a formula that would take the selling price and then cut it down into those value ranges if I am making any sence.
Can anyone help me with this one?
Any help well appreciated.
Cheers,
Albert