(Top layer) 0 pistons required. ((0 + 0*16 + 46)^2) - 0 shulker boxes of redstone.
Note: This accounts for 46 blocks of overhead on the diameter, which is the amount required on the top layer to have your desired diameter on the bottom layer.
(5 layers) 0 pistons required. - 0 shulker boxes of redstone.
(Note: This is 0 overhead; 100% of the total cost.)
(5 layers) Rough time estimate: 0 (real-time) days. (Running 2: 0 days.)
This page assumes you are using exactly one instance of this 3-way bedrock breaker per layer.