Their excuse is that it is for "special handing" which equates to Hazmat. And yes, it is a bit higher than most, but then again it is Gander Mt.
It is similar to buying something advertised as $19.95 +$15 shipping and handling. To many business models this is just a way to seem like they are keeping prices low and making it appear to the customer that the extra fees are out of their control, while at the same time pocketing the money.
Extra costs for shipping, handling, online fees, etc. are a big reason I choose to shop locally whenever I can. It helps support my neighbors gunshops and is seldom more expensive once you add up all the cursory costs involved in mail-order