Yes, you can sell back equipment that you no longer use to the World Golf Tour Pro Shop.
To sell back any equipment you do not want to keep click on the EQUIPMENT tab from your Profile page on the website. From there you will see a button titled SELL EQUIPMENT. Click that button to begin the process of selecting which items to sell.
The credits you can receive for selling each piece of equipment will be displayed under the SELL FOR column.
Equipment that you can sell to the Pro Shop will be listed on the page and will have a checkbox for you to click if you want to sell the item. If a club is currently in your bag the word "Equipped" will be displayed. You cannot sell back a club that is in your bag. You will need to remove the club from your bag before you will be allowed to sell the item. The total value you will receive for the equipment you have selected will be listed in the TOTAL VALUE box at the bottom of the page.
You will receive your credits immediately after confirming the items you wish to sell.
Yes, you cannot sell back the WGT Starter clubs that were given to you when you first joined WGT. Also, you cannot sell back golf balls, whether they have been used or not.