Random OpenAI question: While the GPT models have become ever cheaper, the price for the tts models have stayed in the $15/1Mio char range. I was hoping this would also become cheaper at some point. There're so many apps (e.g. language learning) that quickly become too expensive given these prices. With the GPT-4o voice (which sounds much better than the current TTS or TTS HD endpoint) I thought maybe the prices for TTS would go down. Sadly that hasn't happened. Is that something on the OpenAI agenda?