From my own experience, about two years ago we built an AI form builder tech demo on top of our platform. We open-sourced it (https://github.com/chatbotkit/example-nextjs-ai-forms) to see if there was community interest. Not much. Since it wasn't our core product, we pivoted and turned it into a low-cost Typeform alternative with unlimited forms - formshare.ai was born. And while we have seen some modest commercial success, I wouldn't claim it's anywhere near Typeform's scale.
The takeaway here is that for this project, even though it wasn't our primary focus, leading with open source and undercutting on price didn't prove to be an effective strategy. If anything, charging too little initially will only devalue the product and attract the wrong kind of users - the ones less likely to convert or stick around for the long term.