There are many stores that will try and steal your card details as well as others that will try to sell items at prices that are too good to be true. Students are prime targets for these kind of scams as they will be attracted to sales and student discount.
If a site tries to gather payment through bank transfer do not attempt it as stores should always accept secure payment methods like Paypal.
Don’t just see a padlock and assume that the site is secure, it could be owned by a criminal and your data will just be securely sent to them. Check the full website address before entering payment details. Over 90% of fake online stores have a padlock on them.
If an item is being sold by an unknown website for very cheap it’s probably a scam. This also applies if an online store is selling a highly sought after item that is not available anywhere else at a cheap price, then it more than likely will be too good to be true.