Currently I am at 1.6million crow coins. When buying from the crow coin vendor I worry about misclicking the wrong item one day and max buying and using up all my crow coins in a single transaction (I buy from the vendor every night for the daily reset items). Unlike silver you cannot store CC in a central market or anywhere to keep it safe, and saving up enough crow coins for the Nol takes a very long time. 

I propose either a storage for crow coins. Or make it so that when you buy from the CC vendor the boxes you get can be sold to the CC vendor for the same value in crow coins as you spent on them (obviously once you open the box the item cannot be sold to the vendor or can only be sold for fewer crow coins).