It's in their TOS. It's buyers responsibility to read them. Nobody forced him to use coinabul if he didn't agree to their TOS. Is that so difficult to understand?
Look carefully to their TOS:
You are responsible for assuring that any product you order can be lawfully imported to your destination country. When ordering from Coinabul.com, the recipient(purchaser) is the legal importer of record and must comply with all laws and regulations of your destination country.
There are no such restriction. I know this condition because it is not first time I bought something in US. I have been many times noted by the seller: "Be carefull, we are not responsible for your local tax or restrictions."
Look to this:
I can read their TOS three times, I can memorized it, but there is not written "We are not licensed to send gold to Czech Republic".