What component system sometimes approached the price of a single Soyuz crew seat in certain analyses?

The entire Soyuz crew vehicle plus the Progress cargo counterpart.

An illuminating comparison arises when examining the total cost structure of the Soyuz system itself versus the cost charged for a single astronaut seat. Certain analyses suggested that the expense associated with producing and launching the complete, non-reusable Soyuz crew vehicle in conjunction with its companion Progress cargo vehicle was comparable to, or sometimes even equaled, the approximate $80 million fee charged for just one astronaut seat. This observation implies that a vast portion of the expense was linked not just to the fuel or the basic manufacturing of the specific flight hardware, but to supporting the comprehensive ground infrastructure, ongoing research activities, and the entire operational chain required to sustain that capability over decades.