I want to share my great experience with Tony, who works with Martin at IGS in Canada. He helped me sort out exactly what I was looking for, put me in touch with his supplier (who wound up being about five blocks from my work address - small world), and I got a chance to see the stone before buying. When I needed a Sarin on a GIA stone, Tony made sure I got it quickly. He was honest, clear, and infinitely patient. He gave me no sales pressure, always called back when he said he would, and was only interested in getting me the best stone at a fair price. OK, so here are the specs on the stone:

1.00 ct
H
SI1
Depth 61.8%
Table 55%
pavilion angle 41.4
crown angle 31.6
culet 0.4
polish ex
sym vg
price $4270

The stone performs admirably on the Holloway Cut Adviser and, more importantly, it looks fantastic. I'm having it mounted on an 18 ct tiffany-style setting and I can't wait to make my lady's day. Anyway, thanks again to Tony and IGS. I'd recommend them to anyone seeking great service and an excellent stone at a fair price. Thanks also to Morris Kohan, IGS' supplier, who was so accomodating, informative, and friendly.

Thanks for sharing your experience and congratulations with your diamond!

What is interesting for me in your story is that the stone you selected is not "ideal" by AGS standards but is Holloway Brilliant Ideal Cut (BIC). Hence it should look great while cost much less than AGS0.

You did a great homework! Enjoy your diamond!

Thumbs up for Martin and Tony!

With all the tools that consumers have nowadays, I believe that it is possible to purchase a stone that performs visually as well as (or even better than) many AGS0s without paying an additional premium. What I did, for example, was the following: I learned the table and depth percentages that the experts identify as ideal cut. I then plugged those numbers into the pricescope comparison engine for round brilliant cut, not H&A (53-58% for table, 58.7-62.7% for depth), adding carat weight, color, and clarity that I was looking for. This generated a list of several stones. I looked for those that had polish and symmetry rated at very good or excellent.
Next, one can obtain a Sarin for the GIA certed stones on the list one is most interested in (since GIA does not provide crown and pavilion angles), and have the cert for the AGS stones faxed (since AGS certs do contain this information). Then, it is simply a matter of plugging numbers into the Holloway Cut Adviser to get an idea of how the stones will look relative to each other. Admittedly, you need to work with someone who will be patient and spend time with you. But the reward is worth it - you can save anywhere from several hundred to nearly one thousand dollars on a 1 ct. stone. Branded stones seem to me only to offer the consumer a chance to get a brilliant stone without having to take the time to educate himself. But it is fun to educate yourself! And if you can save money while doing it, so much the better.
(Some branded stones that I have noticed on the specialty sites perform no better - and even worse - on Holloway than a stone you can find on your own using pricescope but cost much more. The moral of the story is to do your research and know that you don't have to pay the "informational tax" that a branded stone has added to it.)
Again, thanks to all who posted on this board over the last few months for giving me information and asking the same questions I was asking. What I did now sounds so simple but it took me a long time to be able to get there and fake some basic gemologist knowledge.

Manuel

Great point! Garry should be glad to read this.