Originally Posted by
Bloxorus
I think OP is referring to the 'foregone' Avios you would have earned by paying for the same ticket with cash.
For example, if I do not have status with BA and there is a ticket that costs £100, would award me with 500 Avios and costs 10,000 avios as a reward ticket. Really I am 'spending' 10,500 avios to save that £100, since I have lost the opportunity to earn 500 Avios by purchasing the ticket with Avios.
OP includes also taxes and fuel surcharge on the award ticket.
So using the same example, say the award ticket comes with £30 taxes and fuel surcharge. So you’re ‘spending’ 10,500 to save not £100 but only £70.