Advisors also get involved when it comes time to apply. Buerger reviews applications to make sure they are filled in properly. "You don't want [the college admissions office] disqualifying you because the application isn't filled in correctly," he said.
Buerger also looks through essays and, if more help is needed, recommends applicants consult with a writing tutor. "I had one girl whom I made revise her essay about 20 times," he said. "She was so sick of it, but she got into her top choice."
The essay, advisors stress, is the student's chance to demonstrate his or her unique qualities, and it plays a crucial role in convincing financial aid offices of whether the student is, in fact, deserving of aid.
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Even after the offers come in, the advisor's work isn't yet done. Families need help evaluating the aid packages.
"I have a whole spreadsheet where I put in the offers so we can compare them, apples to apples," Weaver said. He coaches students on how to negotiate with financial aid offices to ask for additional money, insisting that it's important that students do it themselves.
College-funding advisors charge between $1,200 and $5,000, depending on the level of service, but they insist such fees are more than made up by the cost savings.
"Colleges aren't giving a lot of information to the students on financial aid," Weaver said. "The average family is getting penalized for something that their neighbors might know about, so our service helps to level the playing field."
—By Ilana Polyak, special to CNBC.com