We plan to travel next week back to Sydney I saw somewhere at Suvarnabhumi airport they have a 50 percent discount on excess baggage as we will be traveling with qantas does this discount apply to all airlines and do they have a number to call or website.

Thanks

I posted the full contact details of the unaccompanied baggage office in a post in the Airport Forum.

UTFSE with the key words "unaccompanied baggage" and me as author and you should find it easily (if the Search function works for you, it doesn't for me).