Add A Radio Button With Numeric Value To Cost Calculator?

I have a simple form on my artwork website that allows a customer to enter a numer of prints and a number of colours and then calculates a price of the order (for their curiosity only - that is the end of the function).I have now changed the way I have priced my orders and want to make it so that, for instance, if a customer wants 2 prints it will be �150.00 (�75 per print) but 3 prints will be �195.00 (65 per print) and so on the more they order.What I want to do is to add a list of prints from 1 to 10 with a radio button next to each. the user can then select 5 prints.The way my form works right now (see code below) is that the customer enters a numeric value and then the javascript takes the value and multiples by a pre-set "PrintAmount" value.Because that value is constant - I can't make multiples of prints different values (or can I ?) Heres my javascript (form below):

<script type="text/javascript" src="http://code.jquery.com/jquery-1.4.2.min.js"></script>
<script type="text/javascript">
<!--

[code]....