50 EUR / kg (which seems ridiculous to me) is the correct rate. I don't know where in Asia you went but I used BKK and the airport rate for excess is EUR 50 a kg
http://www.emirates.com/english/plan...35f034bb8a95ee
FWIW, my family usually travels with excess luggage and it has (at times) been cheaper to buy J instead of Y because of all the excess baggage fees.