Comment by toast0

The packaging in one of the photos is a MVNO. It's easier to get sims for a MVNO than a carrier, but either way, there's tons of sim card resellers, they have to be getting inventory from carriers/MVNOs. Ask a hundred resellers for 1000 sims each, and you'll get to 100k. 1000 sims may be a lot for some resellers, but is probably small for many of them.