White Box , Silver Arrow

I recently picked up White Box and was sitting in bed reading the booklet last night when I got to the equipment list and was brought up short by the classic "Silver Arrow".

It's listed as Weight 1, cost 5gp. That's fine, but when compared to standard arrows which are 20 for weight 1, costing 5gp.

How the heck does a single arrow with a silver head cost 50 silver pieces? How on earth does it encumber the same as 20 normal arrows. I'm assuming that a normal arrow has an iron head on it.

I put on my "rationalizing head". 

I would expect a standard silver arrow head to maybe be the equivalent of 2-3 standard coins, so there must be much more to this silver arrow than just a silver head. It cant be that the entire arrow is made of silver, that would meet the strange weight statistic but there's no way that would fly from a bow, far too heavy.

So here's what I suggest. The head of the arrow is silver, but also, silver is inset in a thin line along the shaft of the arrow too. This should prevent the monster grabbing the shaft and pulling it out, as the silvered shaft would make that too painful. So now we have a delicate jewellery-level inlaid silver shaft and a silver arrow head. 

Whereas a standard arrow can take a lot of bouncing around in a quiver, this arrow needs protection from the buffeting of adventuring. Therefore the cost of the silver arrow covers the cost of the effort put into its production, as well as a special lined and padded leather holster to keep it safe.