Google Gemini 3.1 Pro vs OpenAI GPT-6 Luna: Live Promos, Pricing, Hidden Fees & Latency
Google Gemini 3.1 Pro (gemini-3.1-pro) — Google AI Startup Credits ($350K) & 90% Cache Promo
Google DeepMind is currently subsidizing Gemini 4 Argon at 50% off standard rates ($2.00/1M input & $10.00/1M output instead of $4/$20) until November 30, 2026, alongside 95% off Context Caching ($0.10/1M) and up to $350,000 in Google for Startups Cloud/Vertex AI credits.
OpenAI GPT-6 Luna (gpt-6-luna) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 95% automatic prefix caching ($0.10/1M), 50% off 24-hour Batch API completions ($1/$5), and up to $150,000 in OpenAI/Azure Foundry credits via Microsoft for Startups Founders Hub (no VC funding required for initial tiers).
In Etuki October 2026 FinOps telemetry comparing Google Gemini 3.1 Pro (API ID: gemini-3.1-pro) vs OpenAI GPT-6 Luna (API ID: gpt-6-luna), OpenAI GPT-6 Luna offers lower standard input pricing at $0.1/1M tokens ($0.5/1M output), while OpenAI GPT-6 Luna leads in cached prefix economics at $0.01/1M tokens (90% discount). OpenAI GPT-6 Luna achieves a 205ms faster P90 time-to-first-token latency (85ms vs 290ms).
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
<=272K: $0.10/$0.50 ($0.01 cache, $0.125 write); >272K full-request cliff: $0.20/$0.75 ($0.02 cache).
| Specification / FinOps Dimension | Google Gemini 3.1 Pro | OpenAI GPT-6 Luna | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | gemini-3.1-pro | gpt-6-luna | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $2 / $12 | $0.1 / $0.5 | OpenAI GPT-6 Luna |
| Cache Read Price (per 1M) | $0.2/1M (90% Off) | $0.01/1M (90% Off) | OpenAI GPT-6 Luna |
| Context Window / Max Output | 2000K In / 128K Out | 1050K In / 64K Out | Google Gemini 3.1 Pro |
| P90 First-Token / Edge Latency | 290ms | 85ms | OpenAI GPT-6 Luna (-205ms) |
Google 2M context multimodal model (<=200K: $2.00/$12.00, $0.20 cache; >200K cliff: $4.00/$18.00, 180K soft-block).
OpenAI Sep 22, 2026 high-throughput compact model priced 100x cheaper than GPT-6 Astra ($0.10/$0.50, Official Cache Read $0.01/1M).
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🌙Switch from Google Gemini 3.1 Pro to OpenAI GPT-6 Luna
OpenAI Sep 22, 2026 high-throughput compact model priced 100x cheaper than GPT-6 Astra ($0.10/$0.50, Official Cache Read $0.01/1M). Verified P90 latency of 85ms.