A devotion to saving 15 percent of pay, a small inheritance and some investment prowess helped Eleanor and Mark Easterlin build a seven-figure portfolio on one military income.

And now that Mark, 49, has retired from his U.S. Navy career, he has landed a great job with a private military contractor that will bring the couple's annual income to $100,700, including his Navy pension.

Despite all that, uncertainty knocks.

Mark's new job is funded through a military contract that could end suddenly, and his specialty -- military linguistics -- could be difficult to translate to the private sector because he lacks an advanced degree.

Meanwhile, their oldest son, 17-year-old Andrew, will start college in the fall, and their youngest, 14-year-old Richard, is just three years behind.

Andrew is a standout student who has qualified for myriad special honors and scholarships to Florida schools that would lower his out-of-pocket college costs to a few thousand dollars or less over four years.

But he and his parents also have been considering a small private college out of state that would cost an estimated $15,000 each year after grants and aid.

"Mark and I differ on college,'' Eleanor, 52, said. "I think we should save on undergraduate costs and spend more for graduate school.''

Mark, meanwhile, admits he's "living in the past,'' not acknowledging that grad school is becoming more and more a necessity for significant careers.

"I hadn't really planned for beyond four years. I'm thinking more about these next four years, that it's the last [financial] thing I'm going to do for Andrew, and because of that I don't really mind paying extra for a private school.''

Both parents have big dreams for their sons, and it's only natural that they would want to share their good fortune to help the boys get a good start in life, said Sharon Watson, a certified financial planner with Dallas-based RAA Wealth Management, which recently was acquired by E-Trade Financial's wealth management unit.

But spending big on a private school for Andrew will tear away at the couple's safety net for retirement and limit their choices for graduate school and Richard's college experience in a few years, Watson said.

Running the couple's finances through several diagnostic tests, including a new retirement income strategist tool from Morningstar Inc., Watson said their finances would be devastated if their income takes a hit at the same time they're paying for college.

Sure, they've got more than $1 million in assets, but that includes the face amount on their life insurance policy and their $200,000 home. Their liquid assets total a healthy, but humbler, $424,450.

"The review pointed out how everything could go wrong. Everything turns out OK for them if they just don't go nuts paying for college, such as pulling out home equity. Their assets just can't sustain that,'' she said. "It was difficult to say because I felt their dream die.''

On a positive note, however, the family is waiting to hear about the final financial package from the private college. If they end up qualifying for more aid than expected, the dream school could work, Mark Easterlin said.

"It's just really good to know what the limits are," he said. "We were at a real crossroads because I felt we'd done a good job saving and had a real good start, but I was at a loss for the next steps.''

That's where Watson came in. In addition to the college planning, she made several suggestions for tweaking the couple's financial portfolio to get them ready for the college years and then retirement.

But the key word is tweaking, not cutting broad swaths through their financial lives, Watson said, explaining that much of their portfolio was working well. Even more important, however, she didn't want to charge in with lots of moves that would generate big capital gains during the years when the family is attempting to maximize their financial-aid options.