Luggage: What if I need to bring more luggage than I am allowed?
There are no fixed prices for bringing more luggage than the free allowance. Some airlines charge a fixed price and others charge a percentage of the normal one-way fare. You should always check the relevant airline(s) for exact prices and rules. Most airlines have information about extra luggage available on their website.
If you have a lot of extra luggage you should investigate if it's cheaper to send it as cargo instead.