you MUST check the agencies' fees. they can be VASTLY different.
when we hired our second helper, we already knew who we wanted, but he was in the PH. we had no choice but to use an agency.
when i asked around, i was quoted anywhere from $2400-3700 for the agency fee. but because he was in PH, he had to take a "course" on being a helper in hk (he was the only man with 20 women on this course... they learned how to use various eletrical machines, how to cook a meal, go to the market etc). this course, i had to pay extra for... some agencies charged $600, others quoted me $6000!!! i kid you not! i wrote it down and showed it back to them to make sure that i'd heard them correctly and there wasn't a mistake!