[NoiseBert69]

A4-sized, 32 layers.. I'd guess something around 1500€ at JLC.

[farkanoid]

~$320USD each at ALLPCB with a MOQ of 5 for their standard 32-layer stackup, but that doesn't include the blind vias. Probably close to $400?

[15155]

JLC will not do blind vias for you under any circumstances.

[willis936]

And 44k blind vias...