Celebrity: Nicole Richie
The mom of two got engaged to longtime boyfriend Joel Madden with a 4-carat Neil Lane sparkler which she helped design, according to the jeweler. The cost is estimated at $250,000.
Replica: Neil Lane Bridal 14k gold Diamond Ring
This 1 1/5 carat diamond ring from the jeweler's affordably priced line has a 14K white gold band and hand-crafted detailing including a four-step polishing process for extra luster. $3,199 at Kay Jewelers.
Photo by: Neil Lane Bridal/Kay Jewelers 
Celebrity: Kristen Bell
Dax Shephard went to Neil Lane to get the fancy-colored emerald cut diamond, set in platinum with small white diamond accents, to propose to Bell. The three-carat Champagne colored stone is worth an estimated $100,000.
Replica: Emerald Cut Diamond Fancy Color Ring
Designed by Jacques Mouw Precious Jewels, this 1.13 carat champagne colored, emerald cut diamond features a similar stone as Bell's gem. But the 18k gold double banded micro-pave setting is the jeweler's own take on the design. 44,950 at amazon.com.
Celebrity: Penelope Cruz
The blindingly blue 3-carat sapphire gem marked Cruz's engagement to Javier Bardem. Its estimated cost: $30,000.
Replica: Natural Sapphire Company Penelope Cruz ring
The company created a similar vintage-style version with a 2.8-carat stone surrounded by a halo of diamonds for $11,500 at thenaturalsapphirecompany.com.
Celebrity: Jessica Simpson
Husband-to-be Eric Johnson purchased this ruby and diamond gem by Neil Lane for $185,000.
Replica: Ruby Gemstone Ring with Diamonds
This 3/4 carat ruby ring fits the Simpson bill, right down to the two surrounding diamonds. The ring, with 14K white gold band retails for $595 at buy.com
Celebrity: Katy Perry
Russell Brand presented his rock star girlfriend with a Hanut Singh original set in gold and estimated at 12-carats. The price has been reported as high as $1.3 million.
Replica: Memorial Page Gold Vermeil Engagement Ring Solitaire
This CZ Solitaire may be sterling silver and weigh only about 3.5 carats but its cost is far more reasonable. $34.99 at overstockjeweler.com.
Celebrity: Scarlett Johansson
The actress sported this 4-carat diamond ring, designed by Sonia Boyajian, worth a reported $120,000 to show off her engagement to actor Ryan Reynolds.
Replica: Davina's Engagement Ring Oval Cut CZ
A thin 14k gold-plated sterling silver band with a sparkling faux diamond looks like the real thing, but doesn't cost anything close to it. $28.95 at emitations.com
Celebrity: Elizabeth Taylor
One of her countless engagements landed the actress with a 33 carat Asscher cut Krupp diamond flanked with even more diamonds. Richard Burton spent $385,000 to profess his love to his lady.
Replica: Sex And The City Charlotte 2.5 ct. Center
See if you can follow this: Charlotte York, the "Sex and the City" character, had her first engagement ring modeled after Taylor's on the show. Then the faux diamond retailer, Ziamond, created a replica of York's ring, which in fact makes it a replica of Taylor's ring. Confused? All you really need to know is that this version is 14K white gold with a 2.5 carat center stone. $550 at Ziamond.com