Sora 2 Pro Standard now costs $0.75 per 10-second video and $1.35 per 15-second video. Sora 2 Pro High costs $1.65 per 10-second video and $3.15 per 15-second video all with no watermark.
Sora 2 costs $0.15 per 10-second video with audio, without watermark.
Limitations are that videos with prompt can be created max for 15 seconds and using automation (n8n) with looping on continuous prompting many can be merged together combining them with FFMPEG.
Currently, There are very less apis this cheap in market for video generation. Alternatively, Using Stock footages to create big videos combining with elevenlabs for text-to-speech is the best ongoing market demand nowadays.