OpenAI Codex Plus plan token pricing increases 10-20x since June 16

According to a GitHub issue, OpenAI's Codex on the Plus plan experienced a sudden 10-20x increase in token cost-per-rate-limit starting June 16, 2026, draining users' five-hour monthly budgets in 2-3 prompts instead of the previous 20+ prompts. OpenAI has not provided an official explanation for the pricing change.