Russian weapons are known for being built very robust. At least those produced for government use.
With little concern for cosmetics, and only moderate concern for precise MOA accuracy.
Several designs have worked and continue to work with very minimal maintenance in third world nations for generations. Dirt, carbon build-up, dust, and not being taken apart and cleaned after use.
Yet they keep working, rarely requiring new components to replace those broken or worn from neglect.
They still wear from use, having a lifespan like other firearms, but they are neglect friendly firearms.
Part of being so robust with poor care on automatic firearms is looser tolerances. Tolerances that reduce accuracy slightly. The older bolt action firearms were robust even with decent accuracy not needing to self-cycle.
The Russians are known for slapping some heavy wood onto some heavy metal on a large production scale. Getting something into the field that will work, and keep working with poor logistical support.
This lack of cosmetics and fit and finish details, plus the massive scale of thier production, combined with the platforms becoming obsolete or replaced by the government and then entering the civilian market accounts for thier price. A price for a level of performance that leaves them well liked by many.
The complete lack of refinement leaves a durable weapon that works but is of low monetary value.
Which then means great deals for us Americans who still have the freedom to buy them.
That will not longer be the case in the future though. Now there is trade restrictions in the United States on such weapons, and most weapons produced since the 50s are select fire. A great deal of import and export restrictions. Laws like the NFA, GCA etc
So the next batch of weapons to become obsolete and replaced will not be surplus that American civilian can purchase.
So enjoy it, it is a relic of an age when armies used weapons the average American could purchase when they were done.
As they have replaced thier AK-47's and AKMs, and they replace thier AK-74s in the future they will not be available for purchase.
Just as the Garand was the last American service rifle that most mere peasant civilians could purchase once they were replaced. Even our own government made sure to destroy hundreds of thousands of 1911 pistols that were civilian legal rather than let them go to civilians as cheap surplus.
The end of an era when surplus went to civilians. When citizens got what thier taxes paid for when thier government was done using them.