I compare as many diamond engagement rings as I can based on the facts: on data, and on specs, and on prices. Today’s value comparison starts with a Costco Emerald Cut 3.23 ctw VVS2 Clarity, G Color Diamond Platinum Engagement Ring.
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Bottom line: You can get a diamond ring with the same specs (or better) from James Allen for about $16,840 less than Costco’s price.
I’ll do the detailed comparison in this article. But if you want to jump straight to the chase, just know that you can get virtually the same ring — with same or better specs — for about $16,840 less at James Allen.
To see exactly how to order it, go to the section below (near the end) which explains just how.
Costco’s Offer: $44,999.99
You can see it live, if it’s still in stock, as item number 1286753 at Costco. It could go out of stock, conceivably, at any time. However, they’re sure to offer additional rings at that price, rings which are very similar.


Costco Diamond’s GIA Diamond Certificate
A 3rd-party lab-issued diamond certificate is simply expected for any even mildly expensive diamond. This diamond is about $45K, so it’s absolutely expected.
You’ll see that James Allen of course also offers a GIA diamond certificate
Shape
The shape is Emerald Cut.
Carats
The center diamond is 3.01 carats.
Total carats, including the accent diamonds and the center diamond, is 3.23 carats. So, we can know that the accent diamonds alone weigh a total of 0.22 carats.
Clarity is VVS2

That’s very decent for this cut of diamond. Emerald Cuts do not create a lot of sparkle, compared to a brilliant cut such as a Round Brilliant. It’s just the nature of what happens inside of the diamonds when they are cut into these shapes.
Because of that, it’s important that the clarity of any Emerald Cut diamond be … quite clear. I’d recommend VVS2 or even higher.
Color is G

G is not terrible, as a color grade. But it’s close to being meh, in my opinion, for a “step cut” which includes the Emerald Cut and the Asscher Cut (which is just a Square Emerald Cut. The regular Emerald Cut is actually a rectangle, not a square.)
The reason is that you can easily see into the depths of a step cut (including this Emerald Cut). That means you can easily see the color.
The setting (the ring itself) is Platinum
The James Allen Offer. Same specs or slightly better, for $30,900

Notice that the clarity is slightly better at VVS1. So that’s in favor of James Allen.
That’s the only appreciable difference. But you save $14,100.
To build the $30,900 ring, or a very similar one, at James Allen, do this.
- Select this setting as the one you want for your ring.
- Then go to James Allen’s diamond selector / inventory search and set your sliders as seen in the image below.

Want to save an additional $10,000 on a diamond ring with the very same specs?
Then choose a Lab-Created diamond. They are 100% identical to earth-created diamonds, except in their origins. That’s it. See the difference in price below. (To to that, you just click the Lab-Created Diamonds button at James Allen and set your filters to look like those in the image below.)

So, is this Costco diamond ring worth it? In my opinion, no.
Since you can get the same specs (or better) for much less elsewhere, I say the Costco diamond ring is not worth it.
It’s easy to get great deals on better diamond jewelry — for less money! Here’s how:
- Scroll up to the section on “How to Get the James Allen Deals.”
- Follow the easy directions there.
- Feel 100% confident that you bought the best diamond for the money
How to search this site to save up to tens of thousands of dollars at trusted diamond retailers, vs most any Costco, Kay, Jared, or Zales ring you’re considering
Search and save. You could save enough for a new compact car. Or a honeymoon. Or several expensive dinner dates. Or that guitar you’ve been wanting.
Read this very short note on how easy it is.