You keep making the same mistake. When you're in the drug store picking up contact solution or toilet paper or a candy bar or condoms or a pregnancy test or hair dye or however you spend your week day evenings, you pass a sale on the invariably overpriced cold medicine and just walk on by.

Stop it. Stop it right now.

Cold and flu season is already hard enough on your body, your mental health, and your wallet, with drug stores carrying an average of 300 cold medicine products at any given time. Why are there so many products? It's not about what you need to remedy symptoms but about your spending power as a consumer, with reports tallying more than $30 billion spent on over-the-counter medication in 2017. The cornucopia of cold and flu products usually results in choice paralysis, as you stand in the aisle facing a barrage of information until you finally select whatever packaging looks more trustworthy or whichever one's had the most memorable commercial.

Don't fall for it. Consider these tips from pharmacists, doctors, and legions of people who barely get by on living wages but who've learned to hack the system during cold/flu season:

1. Buy Generic

Consider this: Pharmacists and doctors who have studied the ingredients in brand name medicine often buy the generic versions for themselves (up to 90% of the time, according to some surveys). With the power of Dr. Google (and all those skills acquired from those spot-the-differences games as a child), you can save a lot of money by just studying the ingredients on the boxes of brand name and generic versions. Learn the generic names of your medication, and you can save 20% to 50% on your cold medicine.

2. Search for Manufacturer's Coupons

If you simply prefer brand names and take comfort in the extra placebo effect, by all means indulge yourself. But you can also go to the manufacturer's website to find coupons. While you're waiting in the check-out line, take one moment to search on your phone to find that brand name medications like Zyrtec, Allegra, Tylenol, and Advil usually offer coupons and savings clubs through their websites.

3. Sign Up for a Discount Program

Similarly, discount programs like FamilyWize, GoodRx, and WellRx are easy-to-use apps that bring discount codes straight to your phone. These programs work with common drug stories like Walgreens, CVS, Target, Rite Aid, and Walmart.

4. Timing (Stock Up!)

Most manufacturers start offering coupons in late October, and when combined with in-store coupons, you can save double. So don't walk past sales on cold medicine just because that office bug hasn't hit you yet. It's best to stock up! Also keep in mind that cold medicine does expire, so check for boxes with the latest expiration date you can find.

5. Ask Your Pharmacist

A little known fact is that pharmacies will create their own saving programs to incentivize customers to shop there. As Caroline Carpenter, financial adviser and creator of the website mycouponexpert.com, told USA Today, "Almost all pharmacies do this, but you have to ask. 'Why?' They don't advertise it." Additionally, some pharmacists will even match competitors' prices if you can prove you can find it cheaper elsewhere.

6. Shop Smart: Don't Duplicate Ingredients

With similar ingredients appearing in multiple cold remedies, it's possible to overdo it and cause more harm than relief. So another reason you should familiarize yourself with the ingredients list is to make sure you don't go overboard with the acetaminophen (Tylenol). That won't help your wallet or your liver.

Ken Majkowski, chief pharmacy officer of FamilyWize, advises, "Most products have multiple ingredients that do the same thing. You just need two: one for day and one for night." Ideally, you should stock up on a non-drowsy decongestant for the daytime and a nice, sleepy Nyquil knock-off for the night.

7. Ask a Doctor for Free Samples

The next time you check in with a doctor to make sure your cough is just a cough and not the black lung or throat cancer (because who doesn't fall into a WebMD spiral from time to time?), ask for a free sample instead of a good-job lollipop. Doctors' offices often have an overstock of common medications like ibuprofen, and there's no harm in asking.

The reality is that medicine is undoubtedly, unfairly expensive, and it's only getting worse. Lea Prevel Katsanis, a former pharmaceutical marketing executive and author of Global Issues in Pharmaceutical Marketing, says, "Drug companies employ many scientists, physicians, marketing people, and others who really are motivated by helping others, but there are some industry leaders who don't get it. They just don't understand that when they raise the price of a drug by 300 percent, they get pushback."

But the good news is: We're all in this together (aside from the 0.8% of the world's population who hold 44.8% of the world's entire wealth, but screw them). So, yes, always wash your hands, get as much sleep as you can, and eat well, but when that cold inevitably hits you, demand to talk to the pharmacist and your local doctor. Self-advocate and demand the best healthcare you can get, and don't stop asking until you get it. As the wise slogan of the Area 51 raid said, "They can't stop all of us." With enough discontent, the system will be forced to change.