The disappearance is going to happen every year. So that's really not the right way of looking at it.

If you're 160 TPs short of Silver, that means that you've earned 440 TPs in the year.

The first 300 TPs went towards qualifying for Bronze, the benefit of which you will now have until 30 June 2013.

So if you're looking for what's actually been "wasted", it's only the 140 TPs earned since then - but that was fewer than half of the TPs you needed to get from Bronze to Silver anyway. Why clamour to get to Silver? What's the benefit to you? Is it worth £400-£500? What use are you going to make of Silver between now and 30 June 2013?

You really need to think hard about this, particularly in your own financial context. Achieving Silver is not an end in itself. Status is only a tool to help you travel, on the occasions on which you do travel.