You are absolutely correct nitpicker. It does only carry 14 1st compared to your 777s 6 and only 76 compared to the 53. And it does burn more fuel.
A trip to LHR using cx website lowest sector prices available of HKD 9500 for Y class HKD56910 for J and HKD 92500 for 1st looks like this:
extra 6 in first = HKD740000
extra 23 in J = HKD 1308930
extra 166 in Y = HKD1577000
total= HKD3625930 or USD 467853
This is the extra on a return flight, so the 380 would burn about 110t fuel extra on that so reduce the extra amount by USD110000, so only an extra USD 357853 for the same slot/crew etc costs. The 380 would only be carrying about 17t of cargo per sector so you could reduce that by whatever extra cargo the 777 can carry.
Now when fuel gets to USD 4250 per 1000kgs it will only make as much as a 777, so I can see your concern here.
No wonder EK is taking those poor old 777s off the ULR flights and replacing it with the 380, how could they afford not to?
The Don