I know i dont have to buy it. But its good to alert people they are paying way too much for silver if thats what they are looking for.
Anyone who is into precious metals will tend to know how much it is going for, and those that aren't but just want a coin can google "Silver price" and it will come up without any hassle. Keep in mind, there is a big difference between spot price, and mint price. Generic silver coins from recognized mints, tend to go for a few dollars over the actual cost of the metal, you are paying for the company that mints it's overhead, as well as cost to produce the coins or bars. There are also collectors silver coins and bars that sell for much more. I've actually bought a few collectors coins for as much as a 400% premium, and then made profit on them. Its up to the buyer to determine whether or not they think its worth the collector value, or the personal value to order. I will probably order at least one, just to own (and I like silver so thats a plus).
If you are still not convinced, look at how much the silver Cas coins are going for. They sure aren't selling for spot value.
TLDR: People are free to judge for themselves whether or not added premium cost is justified. Junk silver sells for spot price, pretty coins and collectors items sell with a higher premium.