Buying diamond ring needs sufficient knowledge to buy at fair price.
Must know the clarity, color, carat, etc.
Buy from wholesaler can get you as much as 50% discount or even more from eBay as you don't need to go through middlemen.
Natural vs synthetic.
Not enhanced vs enhanced.
Certified vs non-certified.
All those tags about appraised retail price is just plain fake.
The diamond industry is a cartel.
You buy it not for investment because you cannot sell back to the retailer without substantial discount.