Of course, up until now, there's been no such thing as a BD fully-inflexible fare. All fares are changeable for £30 plus fare difference (which has worked out well for me on several occasions).

It's not that the OP wasn't prepared to pay a change fee, but to try to apply an additional change fee to an already flown segment, where a point-to-point one-way would be cheaper... Now, that's just silly.

The way round this, of course, is to travel from CDG, where they just put you on any old flight, and upgrade your fare class for fun, too