What was the best purchase you made at Costco?

Seeing the jewelry robbery video in another thread, and saw a lot of comments about the watches and jewelry at Costco (some negative, some positive) --- made me reflect on one of the best things we have purchased from the jewelry department.

About 20 years ago, I was buying my wife an anniversary gift and found a $200 Movado watch, it's very elegant but it was (to me) an inexpensive purchase.

Fast forward to the present day-- my wife was at our local jewellers needing a battery for that timepiece....the jeweller would not sell a battery, saying that it's an expensive luxury watch and we needed to go to the mall jeweller that does luxury watch repair! He told her that watch is now worth over $700.00.

I think that is amazing that a discount purchase from two decades ago has appreciated significantly in value, beyond inflation. She was happy to get a new battery even though it now cost $25 (used to be $5-$10).