Hi there, they will be happy to sell you a seat in business class at check-in, provided of course there is space available on the day.

The exact cost difference however will depend on a variety of factors - not least the fare basis that was used for your original economy class ticket.

The difference between economy and business class fares can often come as a surprise, and this is a high demand route where the gap between the two is particularly marked.

You don't say when you will be travelling but just by way of example, a quick check of fares for this route based on random dates of out August 20th out and back September 3rd shows that Emirates are currently asking $1900 in economy return, but the equivalent in business class is shown as $12,790 return - so a difference of almost $11,000.

Food for thought ......