So, I spoke with an asst manager at the Wall St store...For an upgrade, the new ring does have to be 2x the original purchase price. As far as the trade in value, they take into account the original purchase price, and depending on the condition of the ring (the band, stones, whether the diamonds have been scratched, chipped,etc), they will give you as close to the original purchase price as they can. He wouldn't give me a percentage range of the original purchase price as it really does depend on the condition of the ring, but he said if it's in pristine condition (not damaged) they do try to give credit for as close to the original purchase price as possible. There is no time limit on the upgrade. He said they will work with you as much as they can.