If they prosper and withdraw money after 30 years at a 35% rate, they'll simply break even by using the pretax account.

FORBES: The Deferral Trap

Yet every penny you eventually take from a pretax 401(k) or a deductible IRA is taxed at the much higher ordinary income rate.

FORBES: The Deferral Trap

Their employers would match the Stretched-Thins' Roth contributions just as they did with the traditional 401(k)s, at a 50% rate on up to 6% of pay. (Employer matches are always pretax and go into the non-Roth side of a savings plan, no matter which account an employee contributes to.) Alas, the couple can't afford to open any Roth plans.

FORBES