I've been using playground since march. Pay per usage, model configuration and your data is not used for training. Some months I pay 30 bucks, some 5. It depends on the model and amount.
The interface is a bit worse as it's obviously not made for consumers but it's like the most obvious "cheat code" many don't realise.
Find here: https://platform.openai.com/playground?mode=chat&model=gpt-4-1106-preview