$3400 per month is nearly the highest within SE Asia. If it were $1500 per month I would consider an increase for second contract with good performance.
my friend is currently paying 6000 for her maid who has been working in her home for nearly 10 years.
mine has been working in hk for 4 years before she came to my home in 2002. She has started her 3rd contract this year. she said she wont work for me any more after she has finished this contract even i agree to pay her 4000 /month.