Is it me or do the vendors on this site sell the same diamonds?

[DiamondDealHunter]

Looking through some of my search results, I see the exact same specs on many stones from sametimes three different vendors for three different prices give or take a few dollars. Are these really the same stones or just happen to have the same specs. If they are the same, who do you buy from since most of the vendors are pretty reputable?
Thanks for the info

 

[pricescope]

Many internet diamond vendors are actually brokers i.e., they don't maintain their own in-house stock of diamonds. Most of the stones offered to the public over the internet are listed in the trade (business to business) networks. By offering diamonds via these trade networks, diamond dealers can offer lower prices as their cost of doing business is lower.

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