'The turbocharger pressure sensor in my Golf (TDI, manufactured in 1995, 90 hp) is defective. According to Volkswagen, the sensor cannot be purchased separately. Instead, they offer a new control unit for a whopping €900.'
Good joke .
Don't you have a good suggestion?
Or rather, what does a used engine control unit (ECU) from a scrapyard cost? I doubt they'll let me just have them remove the sensor from it.
On eBay, you can often find complete assemblies for around 100 euros. Otherwise, there should be a separate sensor available in the Bosch product range. Take the part number of the sensor and search for it in the Bosch online catalog.