It's tough to be specific because every chat uses a different amount of compute. And as we add more models they each have their own cost structure. Our messaging of "Pro gets 5x more messages than Starter" is based on averages of how much individual chat messages use up across the platform of all users. Starter plan might be going away in the future when we have more significant features, like document upload. Will likely allow our early adopters to stay on that tier for a while to say thanks. We provide a usage meter in the app so people know where they are at. Always looking to improve the experience, though.