Utter utter madness.... 6,000 a month.... they are playing you like a sucker. 6,000 a year is more reasonable. I thought it was a typo when you wrote it! That you didn't question it/laugh in their faces at the time tells me that you have a SERIOUS amount of research to do about the industry before you even contemplate putting your marriage and kids financial well being at risk.
I am not trying to be rude but seriously do some proper research as to what you might ultimately get paid IF (and its a big IF) you are one of the maybe 10-15% over 40s that ends up landing a job. Take debt repayment cost, mortgages costs etc off that and see if you have enough money to feed your kids....