As I understand it... the gear list is two fold... if you send in gear to be fixed, it must be on that list to qualify for the discounts that your account offers... AND you must have a certain amount of gear in order to "qualify" for the higher subscriptions.
They do not care if the gear on your list is used, they're using that list to limit you from sending in your mom's camera... unless you've added it to your list that is...

To remove gear, click on the Add Products button top right... that will allow you to add via the pull downs OR remove via the X next to each line item.
Platinum CPS Member... (... it's repair insurance for me... 141 CPS points...)