How many known sealed Qubes are out there?
That's the only reason I feel that my asking price is perfectly justified. Finding the loose cart isn't difficult thanks to eBay, but it's still very difficult to find a nice boxed copy.
I was never on board with the whole grading thing, I scoffed at the idea of people grading Star Wars toys 20 years ago. But, I see the trend where graded items do sell for far more than a similar ungraded item. I think at least, it helps put to rest any concerns a buyer may have as to the authenticity of the item for sale.