In Recettear, I've recently found a Very Odd Vase. It sells for around 22 000 gold. This is a great and highly welcomed surprise to me at this early point in the game. However, I find myself being cautious even now as an old man asks me to sell him a treasure item because I don't want to give away my Very Old Vase, in case it ends up being useful later on.
Am I being overly cautious, and is this the same situation as Chantelise, where all treasure can be safely sold? Or is there any reason for me to hold on to it?