The costs are the same,the only difference is that of transport,hotel and food for the London slip.
Agreed. So let's extrapolate this a bit.
What are allowances in LHR these days? 80 quid a day? Allow 60 quid for accommodation per person also (it was 84 quid at the hotel for techies a couple of years back). So 140ish GBP per day per cabin crew. Four flights a day times 15 crew is 60 crew in town per day. I make that to be 8500 GBP per day. Three million GBP per annum on those figures.
Next, factor in how much less the LHR based C/C are paid p.a compared to their SYD counterparts.
My point is that out and back always saves money if you can get the personnel. Why haven't we 'lost LHR and FRA'? Cabin crew essentially lost LHR due to the above numbers. Techies are unlikely to lose it in the short to medium term due the issues GB highlights. FRA is unlikely probably due to not being able to get cabin crew at rock low prices.