How is it that cheap?! I ran three queries on langchain yesterday with two ConstitionalPrompts and it cost $0.22 - made me realize deploying my project for cheap could be expensive quick.
GPT3.5 Turbo pricing is 10k tokens or ~7500 words for $0.02. Though note that every API request includes the entire chat context and charges for input & output tokens. https://openai.com/pricing
You need to check which model you are using, also... LangChain runs through the model several times with increased token count on each successive call.
Yeah, davinci-003 is gonna be gpt3, which is more expensive than 3.5.
One more anecdote: I've been running a half dozen gpt3.5 IRC bots for a few weeks and their total cost was less than a dollar. A few hours of playing around with LangChain on gpt3 cost me almost $4 before I realized I needed to switch to 3.5, though even then it still uses a ton of tokens every chain.