Originally Posted by
flibbly
To stumble off topic a little, I've often seen it said on here that all tickets can be changed to some degree if you're willing to pay.
Absolutely not!
In my experience, while most ET/WT/WT+ fares are changeable for a change fee plus difference in fare, most of the cheapest CE and CW fare are absolutely non-changeable/non-refundable.
If you book CE/CW and opt for lowest fare, it should be assumed (it will confirm when you go through the booking process) that the ticket is a use-it-or-lose-it affair.
Of course if you book ex-EU then the lowest fare tickets may be changeable for a fee, but it's safest to assume with CW/CE that "lowest fare" means "no changes permitted".