This is a comparison of 0.9ct ideal cut, F color, SI2 clarity Round cut diamonds (click the dollar amount to be taken directly to the diamond):

James Allen: $4650

White Flash: N/A

Abazias: $6684

Blue Nile: $6414

Brilliant Earth: $5440

These diamonds are independently inspected and graded by GIA/AGS, which means you can trust their quality. For everything you need to know about buying engagement rings online, please visit http://howiboughtthering.com.