I once so screwed a No Name surge protection and see absolutely no difference between cheap and expensive! Electronic components come anyway, all from China.
The No Name surge protection even has a filter capacitor (filtering of high-frequency interference, etc.) where other renowned manufacturers refrain for reasons of cost it.
As you can also see clearly, all comply with the requirements regarding fire protection.
Overvoltage protection must not be expensive! Now, each one should make yourself ..