What a ripe off

I own a time share at Sabie river sun for the last few years ,as we are moving over seas for a time we would like to sell our weeks time share the price quoted in the in house news letter gives a price of rand 22700.00 for week 10. However when you ring the sales office in Durban ,they quote the wholesale of 8 to 10000 rand the differance ,or cost of selling the unit is 12700 rand ,the transfer fee is 1465 rand . I think that this commission is ******** even including the small amount of tax I was quoted by there office.There sale agent in Durban quoted that they can only charge up to 25%?.?Is this commission Fair or are time share costomers being **********