Unfortunately, the quote is likely correct.
To take a random guess at your itinerary, say you're flying LAX-LHR-FCO / CDG-LHR-LAX, the difference in YQ between WT+ and CW is over $700 per person. See screenshots below. You'll need to give us your actual itinerary for an exact quote but it seems right.
You may well feel it's a rip-off, but there's not much that can be done about it I'm afraid.
