The complaint is usually along the lines of "I paid thousands of pounds for CW tickets and I can't even choose a seat?" If you thought it was a bit off because the tickets had already cost £2,500 (which is hardly an expensive CW ticket), that seems to mirror the common complaint almost exactly.

If they truly had paid for an expensive CW ticket, then they would have been able to choose seats for free. The people who make that common complaint are usually people who've paid cheap CW fares, although not always the cheapest.