What nonsense. In no respect was the S57 series Beretta "lowend".
The Beretta S57E was a nicely engraved quality gun with ejectors. The S55 was the plain entry level, but still of reliable quality.
They were a great reliable gun, but are unfortunately, they are orphans when it comes to spare parts.
They were notably lightweight guns that were great for carrying upland hunting. People who unwisely used heaviest magnum loads suffered the recoil consequences.
It is the same situation for any truly lightweight gun.