How much is an undisclosed amount, anyway?

I often see indie businesses who sold to larger businesses for an "undisclosed amount".

Obviously it'll be more than the usually spoken about multipliers of 4-6x ARR, but I wonder how much.

I'm coming up to $7k MRR and can't imagine selling for anything but a life-changing amount, which would have to be 10x ARR+.

So it got me wondering, do people sell for much past standard multipliers when they have something the incumbents really want?

PS - If you have such story, feel free to DM in confidence, even with a very vague answer!