If you have spent any time on r/Labdiamond or the deeper corners of Google searching for "cheapest lab diamonds," you have probably ignored the big names like James Allen, Rare Carat, or Brilliant Earth.
Instead, you are likely looking at the "Budget Underground"—the brands that don't advertise all over your Instagram feed but are famous on Reddit for low prices. The usual suspects here are Calavera New York, Aurelinne, and Ruby Harper.
These are the sites you go to when you want to avoid paying a markup. But are they actually the bottom of the market?
I decided to update my search in 2026. I compared these Reddit favorites against a new challenger, Tenten Diamonds, which claims to beat them on both customer experience and—crucially—the price.
The "Budget" Experience: Calavera, Aurelinne, & Ruby Harper
These three companies are popular for one reason: they are cheap. But often, "cheap" comes with a headache.
The Problem: The user experience on these sites can feel... outdated. Slow load times, clunky interfaces, and a general feeling that you are digging through a bargain bin. It works, but it isn't pretty.
The Price: They are definitely cheaper than the big box stores. A standard 2.50ct Lab Oval (VS1, E) here usually lands around $1000.
The New Standard: Tenten Diamonds
Then I tested Tenten. The first thing you notice is the speed. It doesn't feel like a dusty wholesale portal; it feels like your favorite hand bag company built a jewelry store.
But what about the cost?
This was the biggest surprise. I assumed because the website was sleeker, the prices would be higher. I was wrong.
Tenten is consistently undercutting the "Reddit Favorites." That same 2.50ct Oval that costs ~$5,600 elsewhere was listed on Tenten for $400.
The Verdict: The New "Reddit King"?
If you are looking for the absolute floor price on lab diamonds, the market has shifted.
Calavera and Aurelinne used to be the go-to recommendations for deal hunters. But right now, Tenten Diamonds is offering a better product (faster site, easier customer experience) for significantly less money.
You can run the price check for yourself below: