Yip, I've had to replace my door mirror on a facelift. VX quoted £210 excl VAT for the frame (metal parts of the door mirror). Another £50 for the bits of primed plastic. Unsure how much the black plastic part was that goes around the mirror. But your looking at around the £300 mark for a complete wing mirror. Not including £50 to get vx to paint your primed plastic bits.
So its a lot of money. It took me more than a month to get a facelift one from ebay, guy took £75 not including postage and I still had to buy a new plastic painted cover (ebay one was broken and scratched to buggery).
For me it cost around £180 to pay for some drunk student t**t to go on a door mirror kicking night out.
You also need to get one that matches your trim level. The Elite trim has memory seats and heated door mirror, think there is 4 different types for facelifts.
My german friend got a quote from opel who said it would cost £150 in total for a complete door mirror. Looks like we're getting ripped off in the UK

Not surprised