extra function modul cart needed

[matangi]

for a customers site I need an extra function for the cart.

 

for every order that is made within the shopping cart,  for one or more selected categories I like to charge an deposit or security amount.

 

Example: You buy spare parts for a car, e.g. a clutch. When you buy it, some dealer give you a refund if you leave your old clutch for refurbishing at his place. Thats the topic.

 

This is what I need - if someone buys a clutch, he pays an extra amount of e.g 100$. When he offers his old clutch his get his refund back, but this is not part of the scripting job.

 

Within the admin area I need a tickbox or select box for one or more categories that I like to choose. If a customer buy articles within these categories, he has to pay some extra deposit.

 

Within the order review I want an extra line with the name e.g. "security payment" and for the amount no taxes just the plain amount.

 

Please ask further questions, if my explanation is too short. Excuse my english.

 

For the work itself, I will setup a demo shop and give access via ftp and phpmyadmin. I like to pay via paypal after the scripting is finished.

 

If you could estimate the price for this job, I am happy.

 

Thank You

 

Matangi