I am not attorney. However, I have filed a claim 
with the post office before. If it is not 
insured, they will pay nothing. 

If you can prove that the employee was at fault 
you stand a chance. But that will be close to 
impossible. The shipper should have caught the 
difference in price. There is a several dollar 
difference between $150 and $1500 in cost (a 
little of $10). Even if they were shipping other 
items, the little screen by checkout tells you 
exactly what is going on a package.

I would ask the seller what they plan on doing if 
the post office cannot assist you. The seller is 
still responsible. Continue after them, otherwise 
coming back 6 weeks after a the last e-mail will 
probably only cause more issues.

lw