Mayday, please don't be offended by my comments but... if you ask the sender to declare a lower value than what the fabric is, you are asking them to falsify official government documents. We've been told (just today, in fact, by our FedEx rep) that the penalty for that is $10,000 per occurrence. So you are in effect asking a stranger to take a risk and break the law on your behalf, so that you can save some money.
Also... if you want your package to be insured, then you have to declare the full value. Otherwise, it won't be fully insured.
And packages can and do get lost sometimes. It's a big world out there!