It's bad enough you have to pay to check a suitcase, but if that suitcase weighs more than 50 kilos, plan on forking more, depending on the airline. And if it happens to tip the scales to few kilos, the price goes up yet again.
To avoid such nasty surprises at the airport, weigh your suitcase before leaving. Easier said than done, right? Most luggage will block the display of the typical bathroom scale, and I've yet to stay in a hotel that even had one.
40Kg Portable Electronic Digital Weigh Scale – Measures Mass Weight Travel Luggage Fishing Outdoors Kitchen Groceries Hanging Weighing Balance