The most expensive diamond engagement rings in Singapore typically are 5-carats or more and can set you back $82,039.33 to S$335,300.75. Unlike those less than 2-carats, the prices of 5+ carat rings significantly increases with the weight of the gem. For instance, a 5-carat to 6-carat ring's price will double, from S$82,039.33 to S$163,445.67. ...Web