DS3 E-Tense: AC Compressor

Mu DS3 E-tense AC compressor expired a few months after my warranty expired. A new one material only cost is over 1000 pounds!

1/ Would anyone know of another AC compressor that would fit as a replacement and do the same job at a normal AC compressor price of around 300 pounds material cost only ?

2/ Would anyone know why is the DS 3 e-tense ac compressor the most expensive in the mass produced car market ?