The cost is two classical bits and one entangled Bell pair to teleport a qubit. You make the Bell pair, send one half of it to Alice (who wants to transmit the

The cost is two classical bits and one entangled Bell pair to teleport a qubit. You make the Bell pair, send one half of it to Alice (who wants to transmit the qubit) and one half to Bob (who wants to receive it). Alice then does a Bell basis measurement on the qubit she wants to transmit and the half of Bell pair she owns. The Bell basis measurement has four outcomes. For convenience you can label them 00 01 10 11 Alice tells Bob the measurement outcome she got (this is the part that requires two bits of classical communication), and depending on which outcome she got Bob has to apply either no correction or a Pauli X, Y or Z gate. This is known as quantum teleportation https://en.wikipedia.org/wiki/Quantum_teleportation https://en.wikipedia.org/wiki/Quantum_teleportation and has quite a long history at this point (proposed in the early '90s and first performed in the late '90s).