Experience with soundproof ceiling?

Our house construction company has offered to install double-layer soundproof ceilings in the living rooms (3 units) on the upper floor to reduce noise coming through the roof. A charge of 1,500 EUR will then be invoiced for this.

I would now like to know if anyone has had any experience with this. Is the additional cost really worth it? When googling, I couldn't really find anything meaningful.

Thank you very much for your answers!

1500 doesn't sound like much - maybe (pure speculation!) so little to make it quickly appealing to the client?! Why not just 2.5 or 3k then, that's not much either...

I'm also technically interested, so I'll pass the question on: