Love the idea. I love there are people working on this kind of tool.
My biggest question is where the data is stored. I think the storage model for the comments should be mentioned in the FAQ. If it is on your server only then I don't think I'd use it.
I would ideally like the comments to be stored as metadata files committed to the repo or inline with the code. I'd probably therefore prefer a tool-user-based pricing model. And I think $100/y would be a fair price per user.
I don't get the repo based pricing. I could have a repo with a single docker file in, or a repo with a million lines of C++. Having a lot of repos forces me onto the expensive per-user licensing. It would be ok at $100-$200 /y but $69/m === $828/y seems too much. That's 1%+ of a senior dev's salary in most part of the world, for one tool.