In the old days a bag of shot was around $18.

In 2006 or so it was up to $42 a bag.

I have five 25 lb. bags of trap shot and have not looked at what it cost now but
I do feel the pain for those that have to buy Factory shotgun ammo, today.

$7 a box sounds about right for trap loads with #8 or 7.5 lead shot but I
would not be shocked to see a box for $10 for the Quality stuff.