Assuming all 64 subagents were running for a full hour (the tweet states just under an hour):

  Throughput                    Output tokens   Output cost
  ----------------------------  -------------   -----------
  40 tok/s  (5.5 low)                   ~9.2M         ~$275
  55 tok/s  (5.5 base)                 ~12.7M         ~$380
  70 tok/s  (5.5 high)                 ~16.1M         ~$485
  750 tok/s (Sol Fast, $75/M)         ~172.8M       ~$13,000

Claude estimates that tool use / input tokens might add 10-15% on top of that depending on exactly how the model went about the task.

Edit: better tok/s estimate buckets based on GPT 5.5 actual speeds since I couldn't find real benchmarks on 5.6 published anywhere. Also account for Sol Fast pricing.