How are some LLM API providers able to charge way less than OpenAI/Anthropic?

I've noticed more and more third-party API providers offering GPT and Claude models at prices that are significantly lower than the official APIs.

Sometimes the difference isn't small either — I've seen providers like VoyageAge and a few others pricing certain models at a fraction of the direct API cost.

I'm genuinely curious about the economics behind this.

Is it mostly:

• enterprise / volume discounts?
• subscription accounts being converted into API capacity?
• regional pricing differences?
• caching and request optimization?
• taking very thin margins to acquire users?
• some kind of shared capacity / routing across multiple upstream sources?

Obviously the first reaction is usually "if it's that cheap, what's the catch?"

But at the same time, infrastructure and API markets often have huge pricing differences depending on how capacity is sourced.

For people who know this space better:

What actually makes these lower prices possible?

And separately, at what point does a discount become too good to trust?

For example, would you be comfortable using an API that's 50% cheaper than official pricing? 70%? 80%?

Curious how people think about the tradeoff between price, reliability, and where the underlying capacity is coming from.