This is a comparison of 0.80ct ideal cut, F color, VS1 clarity Princess cut diamonds (click the dollar amount to be taken directly to the diamond):

James Allen: $2710

White Flash: $3040

Brilliant Earth: $4030

Blue Nile: $4628

Abazias: $4694

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.