If the product quality doesn't match its price or it's used, just write an honest bad review. The seller will chase you by e-mail and give you back 50% or even 100% to edit the review. At that point you just temporarily edit it, get the gift card, and then edit the review back to the honest review.

And then you have yourself a good deal on a used product.

All we need is some AI to automate the above process and make a one-click interface to get discounted used stuff for 0%-50% of the price.