It's a similar deal to the camera on the Mars rover versus the camera on the iPhone.
I'm sure they don't use cheap components, but that's a bit of an overstatment. It's mostly an economy of scale. They're all hand built to a greater extent than mass-produced electronics.
The limited run is a major factor in the price and remember, the price is not really the cost of the materials. They base it on the work involved in building it which is not done in a day. The many electronic devices cars run are often housed in the wheel. This means that during a race, if there is an electrical issue, often changing the steering wheel can cure this if the fault lies within. If these devices were in the car elsewhere, a fault could not be rectified without taking the car to bits.
Talking about supply and demand, all bikes and equipment that are used in pro cycling have to be available to the public. This was done to try to cap costs with rich teams spending crazy amounts on bikes and gaining an advantage based on money alone. The idea was that if they had to be sold to the public, the costs would be kept down. Stupid thing is, they are not homologated, thus if you want to buy the bike the Team GB team use for track cycling, remembering this has no gears or brakes, they say it could cost nearly £100,000. A truly ridiculous amount. However, it's available, but the manufacturers can concentrate on Team GB rather than be bothered with lots of the public buying them. They simply make cheaper replicas for those that want something similar.
Costs with high tech limited items are not related to other things in life. That said, if a rear wing which has no electronics can cost thousands, the steering wheel is probably cheap considering what it does.
Power tends to corrupt and absolute power corrupts absolutely. [Lord Acton]
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