Well, after this came up in another question and after realizing data on this was hard to find online, I pulled out my graduated cylinder and tried it myself.
As noted in comments, measuring sugar by volume is very inexact. I found that simply by pouring sugar into the graduated cylinder and tapping it, I could start with about 110mL and tap it down to ...
I would be surprised if you find a precise enough scale to be useful in measuring saffron in a kitchen.
A half gram of unground saffron will contain dozens if not hundreds of threads, and while ground saffron is less potent, it should still not require very much, so a pinch is probably roughly equivalent to a few strands.