LLM model training costs arise primarily from commodity costs (GPUs and other compute as well as electricity), not locally-provided services, so PPP is not the right statistic to use here. You should use nominal GDP for this instead. According to Wikipedia[0], the median country's nominal GDP (Cyprus) is more like $39B. Still much larger than training costs, but much lower than your PPP GDP number.
[0] https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nomi...