I've never seen anything that says for sure how much they are paid. I believe it is assumed that they too have signed a vow of poverty and get a moderate allowance each month.
When you are thinking of pay though ask yourself what does a nice apartment in Brooklyn on the waterfront cost per month? $2000 - $4000 ? more?
PLUS - All their meals are free; their laundry services are free; their maid service is free; their transportion around the city, the country and the world is paid for them; they have to pay no bills for electricity, gas, water, telephone, internet connection. They pay no income taxes, social security taxes, medicare taxes, no real estate taxes on their free home. They don't have to pay insurance for medical, dental, vision or transportation. I assume all medical, dental, vision care is also provided.
Looks to me like they are not doing too bad. We have several people on JWD that have been in Bethel for years so maybe they can add to or correct my understanding.