Wholesalers usually offer diamonds at much lower prices than what you would pay at a branded jewelry store because overheads like distribution and marketing costs are already eliminated. This means that you are buying diamonds from the same place, at the same price, as the fancy diamond jewelry retailers do.

Dubai is deemed as one of the cheapest places to buy diamonds and rightly so. There's a reason that it is regarded as one of the world's top three diamond trading centers—the other two being India and Belgium.

Wholesale diamonds are cheaper for a few reasons. First, they are sourced directly from diamond mines or cutting factories, which cuts out the middleman and allows the buyer to save on markup. Second, because they are sold in bulk, wholesalers can offer a discount on the per-carat price.

The prices can be just half the cost of a similar ring at a big-box jewelry store. Compared to online jewelers, here's the general observation: Diamonds 1 carat and above have similar pricing, since the diamonds are certified by GIA. Diamonds under 1 carat are cheaper at Costco, since they're not certified.