Why does a specialist ASW frigate cost so much?

Why does a specialist ASW frigate such as Type 26 cost so much?

It must match the capability of an expensive submarine while protecting the troops, supplies, and carrier air power moving with its task group.

A nuclear submarine costing around a billion pounds is the price comparison used here. Hunting that submarine requires an escort capable of confronting a threat built to a similarly demanding standard. The frigate must also protect the task group's movement of troops and supplies, along with its carrier's air power. The argument is that this defensive responsibility makes an equally serious investment in ASW capability necessary.