Dynamic Form

Hi People,

Im stuck wtih this one, i want an order form to show specific prices for what the customer decides they want, for example:
(this is the form)
brochure design
150gsm
quantity 250 (this is what will change the price)
price: ￡250

(Submit form)

if the customer picks “qty: 350” the price would change…and so on…

Can anyone help with this or maybe recommend a plugin?? ive been trying to find out if cforms11 will do the job but i cant find anything on this, and cant seem to see any other plugins that will allow me to do this…

Hope someone can help…

Thanks in advance.

Brook