Since there are batch 2 buyers still waiting on the SC1 Obelisks ordered (and paid for in full, not just a deposit) almost one year ago (Jan. 2017), I don't think there was a deluge of cheap SC1's on eBay.

However, there were many, many batch 4, batch 5, and I think at one point they had even announced a batch 6, Obelisk SC1 miners that no one in their right mind wanted to part with their money for.

Presto!  The "community" decides to fork and now those worthless, parts already ordered, batch 4/5/6 SC1 miners might have some value.

This is Jack's complete lack of surprise.