Questions on Engagement Ring - HELP ME PLEASE:)

[find45di]

So I have finally jumped into the world of shopping for a diamond. I've read just about everything I could find on the 4 C's, and am ready to hear some expert advice on what is truly best to look for, and buy.

I already plan to go with a certified diamond from one of the well respected labs (GIA, AGS, EGL).

I am hoping to get at the minimum 1 full carat round diamond in the center. On the sides I would like to get the small diamonds that are flush with the band. I would guess these may be .10 each? I've seen nice rings that have 3 or 4 of these small diamonds on the side, and then the one round cut diamond in the center.

So with the center diamond, what is considered an acceptible nice diamond? Should I stick with the VS1's and 2's, or is SI1 still ideal? I am hoping to not see any inclusions with the naked eye. I also understand that CUT is extremely important, but don't really understand what numbers I should be looking for. Can someone help me understand CUT?

I am trying to learn the BALANCE of buying a diamond. Give a little clarity for a better cut? Go with a better cut and a lower color? Help me understand a nice balance of the 4 c's.

Lastly, what would be considered an average price for a 1 carat round cut diamond that is nice? I understand that it is hard to put a price unless a specific diamond is in mind so if you can give some examples that would be great.

I've searched around a few diamond sites so you can refer to these:
http://www.pricescope.com/
http://www.bluenile.com/
http://www.uniondiamond.com/

[Yosef]

A good balance I feel is in G-H-I-(and good J's) for color are suitable for rounds, matched with a min. SI2 (0.50-1.00ct) or SI1-VS2 (1.00ct+), and a cut grade of GIA "Very Good" or AGS "Excellent" (not Ideal) as the overall cut grade should yield a very nice diamond for the price.

For princess shape, I think you should still stick with G-H-I and SI1+. I generally like a princess with depth 65-75% and table 60-70%. For 1.50ct+ VS2 is also needed again because it's a lot of stone and easier to see inclusions, and with princess in general inclusions are easier to spot so I would stay away from most SI2's.

Of course there really is no substitute to working with a good reputable jeweler to find you the best diamond that looks visually the best.