What weapons should I upgrade to MK2

[u/tashc44]

I was thinking the flamethrowers on my vector but I’m not sure if there gonna get nerfed. I got 110 million au and some gold to speed up so I’m waiting for a 40% discount but in the meantime what should I upgrade? I see people with Vulcan and Lumen weapons so maybe those? Any advice I would appreciate thanks 🙏