Factory checkup just before selling...

I've been curious about the number of ads for used equipment that indicate the piece has been checked and certified by the factory. It seems like a great deal of expense, inconvenience (some of our stuff is heavy!!!) and time for the seller to round trip ship it. I recognize the value perceived by the buyer (if it's true), but it kind of a red alert to me whenever I see it, like a "only driven to church on Sundays" ploy.

Would appreciate thoughts and feedback from someone that's either done this, or bought a piece of equipment listed as such. Did they provide paperwork?

Oh, and I've got a rare Hummel listed on eBay. It was made in 1883 and is of Spiderman. Best offer.

Suspicious by nature,
Chris