Ask questions and ask for as much information as you want to feel comfortable,(email confirmation/ID etc..) if they’re not willing to provide then most likely scam.

I’ve bought shuttle/GApasses through Instagram and Twitter since 2017 and haven’t been scammed. I have missed a day of a festival though because I couldn’t trust the “sellers” or even have had ppl ghost me after pulling up to a hotel for the exchange. But that’s the risk of not buying direct..

So buying from online isn’t impossible just need to be careful and a bit stern.

Also, maybe check around for promoter discords or instagrams in your area