Originally Posted by
BicesterTerrier
Thanks for the replies and the link, had been looking through that but wondered if anyone had experience of the actual route that might have been cheaper.....
I thought the fixed-price upgrades were exactly that.
The difference between a WT fare and WTP fare, and hence the cost of an upgrade, at the time of ticketing can certainly be less than that. I've seen it in practice at less than £100 on precisely that sector. But that's a different matter entirely.