Last 2 years with Balkan, we had to pre book ski/board bag and paid extra before the flight, give them a ring or it may cost more just to turn up at airport.
I flew Balkan dec 07 and was 20kg, boots had to be included in that weight, sorry not sure about skis as Idont have them. Try giving acall Balkan Holidays.
Spoke to balkan last week and asked the same question was told somewhere between 15 - 18kg, though they could not guarantee this stating it was the airport who make the final deciscion, but if below 18kg there should not be a problem, so i called Manchester airport who told me it was the airline who set the weight!! but if under18kg then it would not be a problem. So no definitive answer but work on 15 - 18kg max, they aos said dont pack th bags out too much because they might not allow it ...
Spoke to balkan last week and asked the same question was told somewhere between 15 - 18kg, though they could not guarantee this stating it was the airport who make the final deciscion, but if below 18kg there should not be a problem, so i called Manchester airport who told me it was the airline who set the weight!! but if under18kg then it would not be a problem. So no definitive answer but work on 15 - 18kg max, they aos said dont pack th bags out too much because they might not allow it through, so i am working on the basis 18kg max and not overfull
Hope this helps