Would love some advice on possible upgrade (too far out of flight so not bidding yet, just been given a straight cost) - I'm flying economy Singapore-LHR on the Friday flight end of Nov. I've enquired and been offered £660 cost to upgrade to premium economy, which I'm really tempted by as it's a 14h flight! Can anyone please advise:

- Is Prem Economy worth it at this price with Singapore Air?
- Can anyone guess at how busy the flight is? And therefore how likely to be offered a better upgrade £ if I take the risk and wait till 72h before the flight?
- Anyone recently been offered bids on this route, and, if so, what price range for prem and business too?

No airline status. Hope the above makes sense, thanks in advance for the help