if i am buying any products, i first call them or mail them, and wait for there support section to reply, after that i will search google with that "program name + Scam or fraud". I always pays with credit card...
I do my usual due diligence exercise. I check the seller's past record. If I like the product or service I pay using my credit card or any payment processor with chargeback feature just a protection in case the transaction turns sour.
I usually trade with only thos people who have good reputation wherever we are trading and also contact them by mail or get a chat atleats with them on some messenger .I trade with paypal mostly as it has charge back feature also
You could definitely follow the tips everyone contributed in this thread. If the seller provided a contact number, try calling them to find out more about the product you are interested in. Checking their reputation is a must, you should know how other buyers find them and their services.
I use add-ons for my browser that can detect phishing and unauthentic sites, I also make sure that the seller or dealer that I'm dealing with has made large deals in the past and that they have a good reputation and feedback from their previous clients.
I use forums like this one, they are the best source, I think, because there are real people here saying what they think! It's a good place to get a lot of opinions!
1. The payments are done through secured link.
2. Whether the seller has provided proper contact details.
3. Would search for reviews of the site on net.
4. I would prefer only credit card payments, so that i can easily go for chargeback in case of any issue.