There are scammers and thieves in all areas of society. Get your driveway done, get your roof done, buy a used car, engage in casual sex, you get the idea. YOU have to be aware of the risk and protect yourself, take any measures you deem appropriate. If it feels iffy run. No its not logical to become brand averse because some slimeball didn't deliver the product and took your money. I buy and sell a lot of stuff here and have never had a problem.
The steps I take (if not buying locally) are:
determine your comfort level for a transaction
ensure that the price is reasonable (not a bargain)
get a real email address
get a real name
get a phone number and call the seller to confirm the number, and deal details, and satisfy yourself that he is for real
I try to pay with paypal if possible, insured up to 1200 I think, and credit card company will reverse the payment if there is a fraud
have the item shipped with a tracking number and if you can't find it in the tracking system within a few days get on it and call the seller
if I am uncomfortable with any of the above I pass and move on
If you have any other suggestions I would be happy to hear them.