Until recently, the thickness of PCBs played a negligible role in their cost. This situation is expected to change in the coming years. Denser materials are costlier to procure and laminate as opposed to thin materials that go into the manufacture of printed circuit boards.
If the design of the printed circuit board happens to be highly intricate, the process of laminating it might be a bit expensive or costly. A majority of electronic device manufacturers and users in need of thick PCBs have reported high costs associated with them based on their thickness.
Thinner materials generally make PCBs that use them to fit into a lower cost bracket since you need less material to manufacture them. But since thickness can also be affected by the type of material used, rest assured of higher costs with PCBs made of thick materials.
Generally, the typical thickness of a PCB is 1.6mm, but with times changing, thicker boards are becoming even more expensive or costlier to procure. Also though there has been no establishment of the going rate of the industry, generally PCBs made of thick materials are expensive to acquire.
Still, the overall price of a thicker PCB may be significantly higher, especially if it has got an increased aspect ratio. Multiple layers make the printed circuit boards slightly thicker, an aspect that makes its cost to be high also.
While different manufacturers of PCBs will charge you differently depending on the thickness of the board, generally, thicker boards will cost more than thin ones.