I would like to put a button on a product page that a person can sell a item to us. Here is what I was thinking.
Want a functionality where user can sell their existing games to me (Many Games).
When user clicks button “Sell To Many Games” the customer gets few $ added to user account. (if user is not registered or logged in, user needs to register and login first)
Customer can use the available amount in their account to purchase other games from website. It would show up as a credit in the shopping cart, subtracting that total from anything the customer is purchasing.
If the customer is only selling to website in their visit and want to checkout, then a option during checkout in drop down of adding their credit to account balance or having balance sent to the customer via paypal.
I am looking for where I should start modifying this. Should I make a new module? Make a new second shopping cart for selling that then ties into regular shopping cart? I see that I can buy extensions that will give function of giving store credit. Would it be easier to buy that extension and modify it?
Some general direction of where to start would be appreciated.