Is DeepSeek: DeepSeek V4 Flash 0731 or OpenAI: GPT-5.5 cheaper?
DeepSeek: DeepSeek V4 Flash 0731 is cheaper ($0.45 / 1M tokens input / $1.33 / 1M tokens output) vs OpenAI: GPT-5.5 ($5 / 1M tokens input / $30 / 1M tokens output). Actual cost depends on your input/output token mix — estimate it with the pricing calculator.