We paid the $9.87 and picked up the package today. It was in fact from the Space Services company that I ordered the star certificate from. The fee was for tax and handling. (aka Customs fees)
The reason for the stupid charge was because on the customs declaration sticker, they wrote that they shipped software (valued at $19.95) along with the certificate (value $9.95), for a total value of $29.90 USD.
When I first saw it I thought, "They sent another copy of the software with the certificate... perhaps they re-sent the entire package that I ordered previously?"
We opened it up, only to find just the replacement certificate. No software. Nothing else. That's what I expected. But why on earth would they write that software was included and then not send any?
So basically I paid taxes and handling fees on an incorrect value of the package. Had they just listed the certificate, I'm pretty sure I wouldn't have had to pay anything.
Anyway, I sent them an email when I got home. We'll see what they have to say. Hopefully they'll do the right thing and refund me the $9.87 on my credit card.
It's rather funny that I never had to pay anything on the first package, despite the accurate values written on the sticker. Go figure.