$5K KUZMA TONEARM FOR ONLY $690! Gryphon Diablo for Only $699!

Yes, I agree more needs to be done. I have been ripped off multiple times to the tune of thousands of dollars (hard work at an hourly wage by this un-retired, hobbled working senior citizen) and had PayPal side with a scammer on a McIntosh integrated because the scammer delivered a .10 pound package to general delivery in my mailing address’s city of record. AG was no help. 

Scammers will always be with us.

As they are rarely caught the best solution is to drastically up the penalties for those who are.  The US is very good at severe penalties.  Shall we say 3 years prison for a first offence, 20 years for the second?

But we must just all be on our toes and operate safeguards.  As has been said, if the offer is a crazy bargain it must be a scam.  Scammers rely on our greed.

Zero feedback on these vendors

It isn't going away. As a matter of fact, it will probably get more intelligent. All you can do is protect yourself. Be vigilant. Don't buy if it doesn't seem right. Not buying it on the front end is much easier than buying on the back end and asking someone to correct the indiscretion. You can not expect the moderators to fix all of the unsavory transactions.

Sad thing is - even if the user id gets flagged the dirt bag might likely create another user id and repeat his antics.

same thing happened on ebay but in that case it was account theft (at least thirty) with which the scammer or scammers sold the same items with misleading titles and payments external to ebay; I reported the scam to ebay with links and screenshots for several months and the staff never did anything until I picked up the phone and was able to talk to a real person who took an interest in this problematic case which resulted in blocking the ads permanently scammers ... but I had to fight a long time to get all this.
Today a flight by plane costs relatively little and seeing for yourself the object you want to buy is the best thing!