If the offer is too good to be true then it's normally a scam.
If the user is new to the platform, it's a huge red flag.
Another easy way to tell if the ad is a scam is to download the pictures in the ad and upload them in a Google Reverse image search.
images.google.com/Scammers re-use real images from other advertising platforms around the World, so if you find the same images from another legit seller, then it's a scam.
Here is an example of a previous scam:
www.seabreeze.com.au/forums/Kitesurfing/General/scammer-?page=1Christian