I have one of those oooold Starbucks mugs with a typo. It says "briht" instead of "bright." Stores that got them were ordered to destroy them, specifically not to take them home or give them away. I heard rumors of them being sold on eBay when they came out (7 or 8 years ago) for upwards of $100 and then they were pulled at the request of Sbux because they were, technically, stolen property. The employees who posted them for sale fired for stealing.
Or so the legend goes.

It's stamped 056 inside. Does that mean it was #56 of however many were made & shipped?

Is it possible that this thing is valuable to a Sbux collector?

Just curious. I've had it for years and it came up in conversation the other day with someone who was drinking out of it, and we speculated over whether or not it has any value.