𝗛𝗼𝘄 𝗜 𝗖𝘂𝘁 𝗠𝘆 𝗔𝗜 𝗖𝗼𝘀𝘁𝘀 𝟲𝟬% 𝗪𝗶𝘁𝗵 𝗧𝗵𝗶𝘀 𝗥𝗔𝗚 𝗦𝗲𝘁𝘂𝗽

𝗛𝗼𝘄 𝗜 𝗖𝘂𝘁 𝗠𝘆 𝗔𝗜 𝗖𝗼𝘀𝘁𝘀 𝟲𝟬% 𝗪𝗶𝘁𝗵 𝗧𝗵𝗶𝘀 𝗥𝗔𝗚 𝗦𝗲𝘁𝘂𝗽

Three months ago, I almost fired a client.

It was not because they were difficult. It was because their LLM bill was eating my profit. I charged $4,800 to build their RAG system. By month two, I spent $3,100 on API fees just to keep it running. That is not a business. That is a charity.

I rebuilt the entire pipeline. I switched to DeepSeek and changed my vector store setup. Now, the same workload costs $410 a month. The accuracy and quality are the same. I reduced my costs by roughly 87%.

Here is the playbook.

The problem with most AI bots is not the engineering. The problem is staying profitable when clients run 40,000 queries a week. I used to use "safe" models like GPT-4o. Those models do not pay the mortgage.

I started tracking every request. I looked at token counts and cache hits. I realized most spend went to trivial questions. People kept asking "what is our refund policy." These questions hit the same data every time.

My old setup used GPT-4o for everything. Every simple question cost me $0.014. Forty thousand questions a month cost $560 just for the easy stuff.

My new setup uses a smart routing strategy:

• 80% of traffic goes to DeepSeek V4 Flash. • 20% of complex tasks go to DeepSeek V4 Pro. • Trivial tasks go to GLM-4 Plus.

The cost difference is massive. DeepSeek V4 Flash costs $0.27 per million input tokens. GPT-4o costs $2.50.

Here is how I keep costs low:

• Cache aggressively. I cache any question asked twice. A 40% cache hit rate saves thousands of dollars.
• Route by difficulty. Do not use an expensive model for a one-sentence answer.
• Use a fallback path. If one provider goes down, have a second model ready.
• Watch quality. I do weekly spot-checks to ensure accuracy stays high.

I use ChromaDB as my cache. For a support bot where most questions repeat, this makes many queries nearly free.

You do not get rich on the build fee. You get rich on the monthly retainer once the client relies on your system.

Source: https://dev.to/bolddeck/i-cut-my-ai-costs-60-with-this-rag-setup-full-breakdown-2a0