This is a comparison of 1ct ideal cut, E color, VS2 clarity Radiant cut diamonds (click the dollar amount to be taken directly to the diamond):

James Allen: $5240

White Flash: $5402

Blue Nile: $5610

Abazias: $5621

Brilliant Earth: $5710

These diamonds are independently inspected and graded by GIA/AGS, which means you can trust their quality. The quality of these diamonds is identical--the only thing that is different is the price.