While engagement rings can be purchased year-round, certain times of the year offer better deals than others. Typically, the best time to buy an engagement ring is during the holiday season, between Thanksgiving and Valentine's Day.

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.

Sotheby's, your best and most reliable resource for selling your diamond rings, necklaces, bracelets and other jewelry, holds the current auction record for the highest price paid for any diamond or jewel.