If you ship a lot/ship expensive cards you might consider private insurance as you can pay a huge portion of your annual premium in saved insurance costs that you no longer have to pay to USPS/UPS/FedEx. Not to mention you get the benefit of covering your entire collection every day of the year.
With this insurance you never need to buy any when you ship, you only need to follow the carrier and signature requirements stated by the company (which are based on the value of the item you send). I, and I think many others on the board, use these guys (
https://collectinsure.com/). If you lost $50 it wouldn't be worth making a claim b/c, if memory serves, that is the deductible, so in this case you would probably be SOL.