Pricing isn't hard, but it can be hard.
I'd love to help you out, but because I don't understand the use case enough, I don't think I'd be a valuable resource.
I've used Notion databases, but didn't even realize what it was.
Do people join just one Notion database to one google sheet? Or is it multiple? Is it really about sharing data between the two? Is Notion the starting point? Or is Sheets the start?
Are you targeting people who want more power from Google sheets (sharing the data in a way that is more consumable), or do they in Notion, and find themselves copying data from Google sheets. It's a subtle difference, but an important one for marketing.
Again, this comes down to what is the best use case you can find to describe what people do. Do you have a trend that you have seen with how most users are using your product? As in, they have a forecast in sheets, and want to link that up with data about the products they're selling which they have in a notion database, as an example? Or they have their marketing plan in Notion, and the tracking data in google sheets, and they want a way to display them all together?
This sort of thing should help you tell a clearer story for people like me that "almost" get it, but not quite.
Once you know those details, that can help you understand the customer user, and how many databases/sheets the customer may have. That helps you segment who you are targeting, what they care about, and what they understand so you can appeal to their pricing needs.
Does that make sense?