This is a comparison of 1ct ideal cut, F color, VS1 clarity asscher cut diamonds (click the dollar amount to be taken directly to the diamond):

James Allen: $5040

White Flash: $5589

Abazias: $5937

Blue Nile: $7614

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.