The round you either love or hate. For a long time .380's were the necessary caliber choice if you wanted a relatively concealable pocket auto that also had some push behind the projectile. There were and still are two crowds kibitzing about the .380 ACP. One side says: "WAY too underpowered!" The other side says: "It's PLENTY and many European police forces carried it for decades!!"
Whatever you think about the .380, it is another John Moses Browning design which makes it important. John Moses released it in 1908. It is the 9mm's smaller sibling, called 9mm Kurz in the old country. Pocket pistols made it a permanent fixture: small guns carry easy and the .380 feeds them.
The paradox is price. Less cartridge somehow costs more than 9mm, because volume rules manufacturing and 9mm has all the volume. Loads run 85 to 100 grain.
Practice ammo tracks scarce in every panic, so buying deep in calm times is the .380 shooter's edge. Not always easy to find but case deals from foreign manufacturers are out there. Watch the quality on your .380 bulk buys as there is a wide variation in offerings.