A cheap dorm room these days can be around $800-900 a month, and dorms aren't generally coed, so his married status would have made that a much more expensive option. The car was probably required for the job, and the time required to find a new job isn't feasible when you are working 80+ hours a week to keep everything afloat.

Moving is expensive, and would have required both him and his wife to transfer schools. That requires long term planning and isn't a feasible option for an immediate crisis.