Q about BA
 

I'm taking a trip with my wife and kids on BA (ORD-LHR). I don't have any status on BA, but am interested in purchasing upgrades. Has anybody (without BA status) had experience in purchasing upgrades from BA at the counter? I understand that they typically will offer a lower cost for upgrade at the counter. Do you know what I should expect to pay to upgrade 5 from WT to WT+ or NCW?

You should do a search on this on the BA Forum as I know this has been discussed. As I recall, there are not any great discounts in doing it this way. And I have to say, WT+ and NCW run very full on the flights I have been on out of LAX, so I would not count on anything being available. In my opinion, it is well worth the money to at least upgrade to WT+ by reserving in advance. It is not a huge amount and certainly makes the trip much more comfortable.

What kingsroadgal said - there's a sticky on the BA forum and I think the costs will be in there.

However, bear in mind that World Traveller Plus only has something like 24 seats in it - the chance of 5 not having been sold seems slim and even then you're likely not to end up sitting together if you wait until the airport.

Also, these upgrades never seem to be offered out of Heathrow, only for inbound flights.