I don’t know how easy it would be to compare opaque and translucent materials because they are using different rendering paths (differed vs forward) and they support different features.
If we are talking strictly about performance then I would say the main thing you need to look out is the instruction count and sample count of the material more than anything else.
I’m not that familiar with masked materials but as far as I know they are not any cheaper… if the opacity is at 100% then it should be almost the same as opaque material (probably with a small extra overhead) if the opacity is less than 100% however then you could run into overdraw.
Dither Opacity is probably a bit more expensive since it’s masking + fading calculations and whatnot.
But as always… this all completely depends on your game (and your hardware) so there is no crystal clear answer here… you should profile your scene and use the shader complexity view to find potential expensive shaders.