The point is not cheapness but that you don’t care about the future of that phone. It’s only a tool for the protest, if it lasts longer that’s good but you expect it to get confiscated and never given back, you don’t care what cops did with it if you get it back, it does not have data you need in your daily life or anything irreplaceable, and you’re not really afraid that it gets destroyed by accident or maliciously.