The cost of the LLM isn't the only or even the most important cost that matters. Take the example of automating AI research: evaluating moves effectively means inventing a new architecture or modifying an existing one, launching a training run and evaluating the new model on some suite of benchmarks. The ASI has to do this in a loop, gather feedback and update its priors - what people refer to as "Grad student descent". The cost of running each train-eval iteration during your search is going to be significantly more than generating the code for the next model.