Some people want newts badly and will pay insanely high prices for them and an Import/Export license is only $100/year (for commercial purposes) which is a small price to pay.
One good possible reason it doesn't seem like anyone has done it legally may be because of the process required to bring live animals into the country. When the plane lands, before you even get to look at them, USFWS officers need to inspect the shipment in a secluded part of the airport away from the public. During the inspection they check for things like proper packaging and hidden contraband, but more importantly, they look over the declaration and make sure the animals in the shipment match what has been documented. In order to do that they need to make a positive identification. From personal experience, I can assure you these people will not be able to positively identify salamander eggs. Not only would they not know if the egg was laid by a salamander, frog, sasquatch or fish, they certainly wouldn't be able to identify the species.
Actually, they can have a difficult time identifying full grown adult salamanders, even with a field guide. Even if the salamanders had their scientific names tattooed on their forearms and foreheads! Hahaha!
