Pretty sure this is what is causing the whine on my sport, read a thread on here where someone said he got this done at a main dealer for (iirc) £127 with a small discount on the part which is usually £101 and a slightly reduced labour rate cause it was an older car. Apparently the manual states it is a 30 min job so they won’t charge you more.
I have just rang my local garage and they quoted me £700 claiming 4 hours labour!? Did I miss something? Maybe that was to remove the whole compressor rather than just the pulley? Confused!