Subscription-based ChatGPT-powered products

Hi everyone, I am seeking suggestions and opinions on a serious topic. Since the launch of ChatGPT, many products have been created using their API. I have built a productivity tool called Virtuo(https://virtuo.simplef.net/), which is a Chrome extension. My plan is to sell it for a one-time fee, and the user will use their own OpenAI API key. This way, the OpenAI API cost is minimized. I remember playing with the API a lot before creating the extension, and I couldn't even use all of my free credits. Last week, I started getting early adopters and feedback from some people. One of them suggested making it a subscription-based service. I have noticed that many tools are starting to use subscription systems, like Merlin(https://merlin.foyer.work/pricing/), which offers subscription packages by limiting the number of queries and words. However, I don't think that users can fully utilize their credits with these packages. On the other hand, using your own API key is totally worth it because it offers a pay-as-you-go system. What do you think? Is a subscription-based ChatGPT-powered product worth it at this time, or should I continue with what I did for Virtuo, where the user uses their own API key and pays as they go to OpenAI?