In my opinion,at the time it was purchased. Others will disagree and that's perfectly fine.
Retail?
When listing an item's new retail, should the price be the current retail, or the price of the item at the time it was purchased? If you know someone bought an item for $2,500, it is 3 years old, and the say the current price is $3,300 and are asking $2,200 - is this appropriate and honest or somewhat not?