If you have US over $10,000, go to a bank, open an US account and ask the bank to issue a money draft to "Accu-Rate". Then you could have a "commercial rate" at Accu-Rate.
e.g. when I exchanged the US two weeks ago, the rates were:
Bank -- 1.512
Accu-Rate 1.524 for US cash
1.525 for US check(not personal)/money order/money draft
1.536 as the commercial rate (the one I got for over $10,000)</HTML>