This is a comparison of 0.90ct ideal cut, E color, VS2 clarity Round cut diamonds (click the dollar amount to be taken directly to the diamond):

James Allen: $4860

White Flash: $5499

Blue Nile: $5599

Abazias: $5927

Brilliant Earth: $6430

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.