The closest alternative to Claude Fable 5 is GPT-5.4 — comparable intelligence (56.8 vs 64.9); for a cheaper option, Claude Opus 4.8 runs $5.00/M vs $10.00/M; for more speed, Claude Opus 4.7 hits 92 t/s.
GPT-5.4 is the closest alternative to Claude Fable 5, with an Intelligence Index of 56.8 (Claude Fable 5 scores 64.9) at $2.50 per million input tokens.
Yes — Claude Opus 4.8 costs $5.00 per million input tokens versus $10.00 for Claude Fable 5, while staying within ~8 points of its Intelligence Index.