Jill just turned 30. After consulting a financial planner and laying out her retirement goals, she calculates that she will need to have a balance of $660,000 in her retirement account to supplement Social Security she plans to start collecting when she turns 67. She plans to start saving immediately and to invest her funds in a market index fund that is expected to have an annual return of 7% over the 37 years she will be saving money for retirement. How much money does Jill need to save and invest every month in order to reach the necessary balance in her retirement account by the time she retires at age 67?