That accounting exists because DeepSeek doesn't need to exist for me to use 4.1 Flash. If Anthropic goes under, Claude probably just ceases to exist.

That accounting doesn't make sense when looking at future models, but if you're evaluating the current state it makes sense to ignore training costs for companies that don't pay them.

You can also get subscriptions for the open models, which are typically much cheaper. It's not crazy popular because the open model crowd switches often, but they do exist if you want a firehose of tokens.