You guys should look into collector's insurance, that way your stuff is covered at all times, including in the mail. (In other words, you never again have to buy insurance when shipping.) With Collectibles Insurance you can get a $20-30 k policy for like $150/year. If you ship a fair amount, or send expensive cards, then you pay for a huge chunk of the premium in saved insurance with the shipper. You have to follow the shipping rules (below) based on the value of the item and schedule anything over $5000. Note: the rates are different based on whether you are a dealer or collector.
http://collectinsure.com/
There are a few threads about these policies and many board members have said they have made claims and had no issues with this company.