Ammunition prices fluctuate drastically with global and national events. In 2021 when COVID hit 9mm cost roughly 70 cents a round. Today it’s around 19 cents a round. There’s a buy cheap stack deep philosophy practiced when buying ammo.
A competition shooter or someone attending a class can easily shoot 1,000 rounds over a weekend. Buying in large volume when prices are low means that weekend costs $190 not $700.