According to the Sharn sourcebook: under the Galifar code of justice, it is illegal to sell relics of previous civilisations fo personal gain. So technically, the horns, circlet, and inactive Talisman of the Sphere recovered from the Whispering Cairn are all contraband.
Fun times! prepare to be searched at the gate!
A couple of points:
- This is largely in reference to Xen'drik goods, 'cuz Breland wants a cut
- And, as pointed out in that self-same book, most of the guards are eminently bribable. :)