Unfortunately a sad part of all TCGs is there are people trying to scam you. Some people buy and sell fakes but the problem comes when they say they are real. Other common scams include paying and not sending. Selling goods that they don’t own. Reverse charge buyers are even something that could be an issue.
The general premise behind not getting ripped off is simple, if it don’t feel right don’t do it. Now that sounds simple right? But if its a risk, don’t do it. There are plenty of risk free or at the very least risk mitigated buying opportunities out there.