A good site to see if the proposed purchase site is a scam or not:
www.stopgunscams.com
Enter the site name and if they have in their data base, you'll know. Their database is constantly improving.
If the site you want to purchase is not listed, that is a good thing but, it may be new and not in their database. So here are some other things to check;
BIG Red Flags:
Are their prices REALLY good? If they are, be wary.
When you go to pay, do they take major credit cards? If they don't don't purchase from them.
If they only take: crypto currency or paypal knock-offs don't purchase from them.
If you are scammed, please report to Stopgunscams.com and post on this sight.