Benchmark.

GPT-6 Astra or Fable 5.1 for coding?

Both list at 10 dollars and 50 dollars per million tokens, so the headline price is a tie. The cache read rate is not, and on a coding agent that is where the bill actually lives. A head to head on the published coding benchmarks, the cost that the price list hides, and an honest answer about which we would reach for today.