The welcome respite that is sending your kids back to school after a long summer comes at a price, one that's driving a surprising number of parents into debt.According to a recent MagnifyMoney survey, more than 1 in 5 parents will go into debt to cover the cost of back-to-school expenses, meaning they'll finance those expenses with a credit card or loan and take more than a month to pay off the resulting debt. Debt or no debt, the cost associated with back-to-school shopping is significant. Nearly three-quarters of parents plan to spend more than $100 on back-to-school items, with 23.8 percent planning to spend in excess of $500.The survey, which polled more than 700 parents on a variety of topics related to back-to-school expenses, also revealed a strong correlation between the pressure parents feel to buy new things for their kids during back-to-school shopping and the likelihood that they'll take on debt to do so.[See: Avoid These Common Pitfalls During the Back-to-School Shopping Trip.]Under pressure. More than half of parents who will take on debt to finance back-to-school purchases report feeling pressure to buy new things for their kids. That pressure to buy new is felt by just 33 percent of those parents not planning to finance back-to-school purchases with debt.It's no coincidence then that among parents willing to take on debt, nearly two-thirds plan to spend $300 or more on back-to-school expenses, with 37 percent planning to spend $500 or more. By comparison, among those not planning to take on debt, only 38 percent intend to spend $300 or more, and only 21 percent plan to spend $500 or more. Nor is it surprising that among parents expecting to go into debt, 35 percent consider the cost of back-to-school supplies unreasonable, compared to just 19 percent of those not planning on going into debt.Retail credit prevalent among debtors. Parents going into debt to pay for back-to-school expenses are three times more likely to use a retail credit card to pay for those expenses than their debt-free counterparts. Among parents planning to take on debt, 17 percent will pay for at least some of their expenses with a retail credit card, compared with 5 percent of parents with no intention of taking on debt.That's significant, of course, because of the notoriously high interest rates that come with most retail credit cards. The Target REDCard and the Walmart Credit Card, for example, carry interest rates of 22.9 percent. Parents financing $300 on a retail card with a 22.9 percent rate will spend an additional $38.50 in interest – more than 10 percent of the initial cost – if they pay off the principal loan over the course of a year.[See: What to Do If You've Fallen (Way) Behind on Your Credit Card Payments.]With debt, comes stress. Back-to-school expenses not only impact parents' financial well-being, but their emotional well-being as well. According to the MagnifyMoney survey, there's a strong correlation between taking on debt and feeling stressed during back-to-school shopping. Parents taking on debt were twice as likely to find back-to-school shopping stressful than parents who are not.Clearly, for the sake of both their wallets and their sanity, it behooves parents to keep back-to-school costs in check and avoid potentially damaging debt in the process. Here are five ways to do just that.1. Set a budget. Nearly a quarter of survey respondents plan to spend north of $500 on back-to-school supplies, 14.6 percent plan on spending more than $700, and 8.9 percent expect to top $1,000. Clearly, back-to-school supplies have become a big-ticket expense, and big-ticket expenses require budgeting. Set and stick to a predefined budget, preferably one that you can manage without the aid of credit.2. Stick with cash. One surefire way to avoid incurring credit card debt is to pay with cash. Among those not expecting to go into debt, 63 percent won't use a credit card to pay for back-to-school expenses. Not coincidentally, 62 percent of parents who avoid using a credit card spend less than $300 on back-to-school expenses. Stick with cash, and you're more likely to keep your costs down and stay out of debt.3. Anything but new. Given the clear correlation between buying new and incurring debt, parents should explore every alternative before buying something new. Whether it's hand-me-downs, thrift stores or just a good, hard look at what's already in your closets, chances are you can find at least some of what you need without paying retail price.[See: 10 Completely Careless Credit Card Mistakes You're Making.]4. Save in advance. Unlike an unexpected illness or a broken appliance, going back to school is predictable. It happens at the same time every year, and you generally have a good idea of what you will and won't need long before you actually set out to shop. All of which means you have ample time to save. Setting aside a little money each month in the run-up to back-to-school shopping can help you keep debt at bay when the time to spend comes.5. Spread it out. Going back to school happens, without fail, at the end of every summer. You know this in February the same as you know it in August. While some back-to-school needs vary depending on your child's grade and teacher, others, such as generic supplies, are fairly consistent. So spread out your shopping (and your costs). If you see a deal in February on something you know you'll need come September, take advantage then and there. Do the same on the other end as well. If there are supplies that can be bought on an as-needed basis throughout the year, instead of entirely up front in one debt-inducing lump sum, then don't be afraid to spread them out. It might feel good to have all of your back-to-school shopping done in one shot, but not as good as it will feel to stay out of debt.25 Ways to Fix Your Finances Fast.