Originally Posted by FlyingNowhere

A thought: Will the amount needed have to keep increasing each year/years?

The current system - roughly based on distance, fare bucket type and class means that inflation has no effect on it (I think!)

In this new world they'll need to keep moving the spend target every year(s) or inflation will eat into it?

Eg say in 10 years time a basic economy return to Spain might cost you £2000, so you'd only need 5 of those to get to silver at today rates (about £10k spend for 'new' silver)