2026年9月12日時点の価格表 Model Context Input Cached Input Cache writes Output GPT-6 Astra Short $10.00 $1.00 $12.50 $50.00 GPT-6 Astra Long $20.00 $2.00 $25.00 $75.00 GPT-5.6 Sol Short $5.00 $0.50 $6.25 $30.00 GPT-5.6 Terra Short $2.00 $0…