GPT-6 Luna vs Gemini 3.5 Flash Lite: cost

For a typical support chatbot, GPT-6 Luna is about 4.5× cheaper than Gemini 3.5 Flash Lite ($38.51 vs $175 per month). Price is only one factor: test both on your own prompts before switching.

GPT-6 Luna vs Gemini 3.5 Flash Lite: prices and limits
GPT-6 LunaGemini 3.5 Flash Lite
Input /1M$0.10$0.30
Output /1M$0.50$2.50
Cached input /1M$0.01$0.03
Batch input /1M$0.05$0.15
Batch output /1M$0.25$1.25
Context window1,050,0001,048,576
Max input922,0001,048,576
Max output128,00065,536

Monthly cost by workload

Estimated monthly cost by workload (USD)
Scenario (per month)GPT-6 LunaGemini 3.5 Flash Lite
Customer support chatbot
5,000 req/day · 1,200 in · 400 out · cache 60%
$38.51$175
RAG over documents
2,000 req/day · 8,000 in · 600 out · cache 30%
$53.64$195
Coding agent
1,500 req/day · 25,000 in · 2,000 out · cache 80%
$79.31$320
Deep reasoning
800 req/day · 3,000 in · 6,000 out · cache 20%
$77.90$378
Batch processing
50,000 req/day · 1,500 in · 150 out · batch
$169$619