Self employed

Since Amazon does not give us full control over the items for 6 months after we receive them, shouldn't the value of the item be its garage sale value in its used condition after that 6 month period? 

 

How do we adjust that on our return, or is it best to simply file with the info Amazon provided, then file an amendment with explanation afterward?  I figure that way you pay up front, no red flags, then MAYBE get your money back...