Most full fare airlines are pretty ok with allowing one more luggage. I have often checked in 2 bags (over the permitted one) to save myself the hassle of carry on luggage. Never had to pay a dime for it. Last week they allowed me 12 kgs extra out of HKG and did not even bat an eyelid for the extra suitcase.
On the other hand a low cost air asia out of hkg was checking the grams on every bag and not allowing persons in the group to club their allowances which one has to pay for in advance