Originally Posted by
Rusland 17
I have noticed that too.
Cost of a return ticket from London to Geneva in economy: £88.
Cost of a return ticket in economy, upgraded to Club Europe using BA Miles: £473 + 18,000 Miles!
This is "by design".
You can only upgrade with BA Miles from the three most expensive economy booking classes: Y, B and H.
In general, it's pretty pointless doing that. BA Miles are better used for upgrades from cabins other than economy.