This is a comparison of 1.5ct ideal cut, G color, VS2 clarity Princess cut diamonds (click the dollar amount to be taken directly to the diamond):

James Allen: $9180

White Flash: $10,275

Abazias: $12,229

Blue Nile: $13,001

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.