7 surprising costs of being a college student you probably wouldn't expect

It's not uncommon for interns to be working for little to no pay. And, it's also not uncommon for these interns to have to pay hundreds of dollars to get their experience outside of school to count for college credit.

Many colleges require students to pay the same price for an internship credit as they would for any other class they'd take in the classroom for college credit. You might be on the hook for several hundreds of dollars if you want credit for your work experience, meaning that unpaid internship can put you even further into the red.

Many colleges will enroll students in their health insurance plans until they opt out, Business Insider previously reported.

Colleges reason that by doing this, they can comply with regulations and make sure each student is adequately covered. And these plans aren't cheap, either — they can cost anywhere from $400 to $1,900 per year.

But many college students won't need these plans. Federal law permits young adults to stay on their parents' health insurance plans until age 26. If your current insurance meets the school's standards, there's no need for this extra expense.

It's likely that your school will offer a waiver process for this charge, and it's worth looking into if you think your health insurance will meet the school's standards.

When it comes to Greek life, there are several types of expenses. First, there are the recurring costs like dues and housing costs each semester.

It's not uncommon to pay around $1,800 each semester in dues alone at big schools like University of Southern California. Schools with smaller Greek systems can see more affordable dues, between $400 and $600 per semester.

Then, there will be other expenses, ranging from simple purchases like buying the fraternity or sorority's group shirts, to buying tickets and apparel for formals and events. Small things throughout the year might also add up, like buying gifts for big-little week, attending group outings to restaurants or events, and even paying fees for not attending meetings or making certain grades.

In small college towns where lodging can be sparse, hotels and vacation rentals will often increase their prices around parents' weekend, orientation week, and graduation week. Parents wanting to help move their student in or out of their dorm, visit for orientation or graduation, or for other high-traffic weekends might find that it's fairly costly to stay near campus.

To dodge these prices, parents can consider taking advantage of hotel credit card perks with hotels near campus, staying farther from campus, and booking early to offset some of the costs. Visiting during non-peak times can also help to make visits cheaper.

Whether you're living on campus or subleasing your room for the summer, you'll need to find a place for your things. And if you aren't able to move all of your things home each summer, that might mean renting a storage unit.

According to data collected by storage unit rental site SpareFoot, the average cost to rent a storage unit across the US is $88.85 per month. But, that varies by your location.

While the average cost to rent a unit in Indianapolis is $63 per month, units in denser urban areas like Boston and Los Angeles will cost about $140 per month. Multiply that by the three months you'd need the unit for the summer, and storing your things could easily cost upwards of $400.

To cut back on storage costs, find someone who'd be willing to split the costs of the unit — you likely won't have enough to fill the whole space yourself, anyhow.

The most expensive hidden cost of college is one many students don't notice until after graduation: student loan interest.

The average student loan borrower owed $33,310 as of September 2018 with an average interest rate of 5%, reports Business Insider's Tanza Loudenback. If you paid the minimum payment of $353 each month for 120 months or 10 years, you'd spend $9,097 on interest alone.

Refinancing your student loans, using the debt avalanche method or making higher payments could help make balances deplete faster.