The closest alternative to Aion-1.0 is Aion-2.0 — comparable intelligence (— vs —); for a cheaper option, GPT-5.4 runs $2.50/M vs $4.00/M; for more speed, Morph V3 Large hits 3.1k t/s; and the best open-weight substitute is MiniMax M3.
Aion-2.0 is the closest alternative to Aion-1.0, with an Intelligence Index of — (Aion-1.0 scores —) at $0.800 per million input tokens.
Yes — GPT-5.4 costs $2.50 per million input tokens versus $4.00 for Aion-1.0, while staying within ~8 points of its Intelligence Index.
MiniMax M3 is the strongest open-weight alternative to Aion-1.0 — downloadable from Hugging Face and self-hostable, scoring 54.7 on intelligence.