[cabaalis]

Matching tshirts and signs for a decent sized group aren't cheap. I see stuff like this often in protests. Who pays?

[SamoyedFurFluff]

In my experience the union pays, both with fees and also through fundraising. See: the Harper collins union strike was able to go 50+ days, including holidays, with the crowdfunding of a supportive literary community.

[fckgw]

The union does. That's one of the things your union dues go towards.

[Animats]

Few unions today have enough money for that. The UAW, maybe.

[jltsiren]

Your intuition fails here. Resources generally scale with the size of the group, while the price per individual goes down. If you order in sufficient quantities, you should be able to get a decent t-shirt with a single-colored print for ~$5.