In Addition To Power, What Else Affects The Price Of Automatic Voltage Stabilizer?

So what are the factors that affect the price of Automatic Voltage Regulator:

1. The wider the voltage regulation range (15%, 20%, 30%, 40%), the more expensive it is in principle

2. The higher the voltage regulation accuracy (1%, 2-3%, 5%), the more expensive it is in principle

3. Configurations that exceed the standard model: such as adding lightning arresters, filters, communication interfaces, installing transformers, etc.