Haiku 5.5 matches Luna's $0.10/$0.50 only under 100k tokens, and a tokenizer using about 1.25x more tokens hides a price increase. Long-context workloads may be cheaper on Luna.
Key takeaways · AI-distilled
Above 100,000 tokenThe chunk of text a model reads and writes in — roughly three-quarters of a word — and the unit AI usage is billed in.Full definition → Haiku 5.5's price rises 5x to $0.50/$2.50 per million, while GPT-6 Luna only steps up at 272,000 tokens, to $0.20/$0.75, so Simon Willison judges Luna the much better deal for long-context windowThe maximum amount of text a model can consider at once — its working memory for the current conversation or task.Full definition → work.
Haiku 5.5 cannot disable reasoning and defaults to medium effort. In Willison's pelican SVG test, low effort cost 0.0936 cents in 7 seconds, while max effort took 5 minutes 9 seconds and still cost only 3.3826 cents.
Anthropic is adding a monthly API credit for Max and Team subscribers: $100 for Max 5x, $200 for Max 20x and up to $500 pooled for Team, claimed under Settings, Billing. Willison notes the credit matches the subscription's own cost.
Anthropic now lets API users disable auto-reload so requests stop when the balance runs out, which Willison says avoids billing surprises. He still rates OpenAI's Codex subscription, usable for personal API calls, the better deal for heavy API users.
Terms in this piece · Glossary
token — The chunk of text a model reads and writes in — roughly three-quarters of a word — and the unit AI usage is billed in.
context window — The maximum amount of text a model can consider at once — its working memory for the current conversation or task.
