i paid 25$ for hornady critical defense 9mm 115gr 25ct and i paid 20$ for hornady critical defense .40 165gr 20ct i don't see where your going with this its like conspiracy theory
Again, I typically don't buy 10-20 rounds at a time. Here is a decent example, in my 2 minutes worth of searching. I often purchase from www.ammunitiontogo.com
1,000 rounds of Winchester White Box 9mm is $279.95.
1,000 rounds of Winchester White Box 40 Cal is $339.95
A difference of $60.00 and that's not even the cheapest 9mm ammo that they have.
Fiocchi is $239.95 per 1,000 rounds of 9mm
Dynamit Nobel is $199.95 per 1,000 rounds of 9mm
Winchester Ranger Nato is $219.95 pere 1,000 rounds of 9mm
When you move into JHP ammo
On sale is Federal HSTs ammo. Looking at the heavier grain 9mm +p, it's the same price as standard HSTs in .40 cal at $264.95
Gold Dots - 9mm is $10.00 cheaper per 500 rounds
So there clearly is no conspiracy theory but rather facts and data to review and verify. Generally speaking, 9mm ammo is cheaper then .40 cal ammo. There is always going to be a sale or a special find where .40 might be the same as or even slightly cheaper but generally speaking, 9mm is going to be less.