There is always demand for a free tier, after all its free. Don't listen to this feedback, freemium is a marketing tool that requires a lot of capital for scaling and additional support, nothing available when bootstrapping. 2usd / month is hard too, because you will loose most of it to transacrion costs. Maybe a yearly or one time fee for up to x comments? The free version could be a trial of sorts, the first 50 comments free.