I think with the end result you are looking for this would be easier to create on a product detail page. On a detail page you could just have the radio group be dynamic and associate the values with a recordset for the prices.
You can then do the javascript to set the value of another form element to the price. For the JavaScript part it should be very basic, it might be just setting the value of an element in the onChange event for the radio group. Here is a link to the W3schools site, it is a great resource for the js stuff:
prop_text_value.asp