Keep in mind that on the GIA certificate it says that it doesn't guarantee that the diamond you have received is exactly what the GIA says it is. I always thought it was as guarantee, but a jeweller got me to read the fine print on the certificate!
You should consider a GIA certificate which is the highest and most reputable grading company in the entire industry. It stands for Gemological Institute of America. research them online and ask any reputable jeweler they will confirm.
in regards to price, it depends but check the rappaport report for wholesale market rate that will give you an indication wether retail price is too high. Good luck.
I got my engagement ring in Aust, but IMO that quote is a complete rip off... My friend got a 1.9 carat engagement ring in Dubai for 40k I think? It's a pear shape so cheaper than than round cut but even so... Not sure about colour or clarity, but he is a good jeweller and her ring has always looked sparkling to me! I think her ring is platinum too...
I would go to a few places and get quotes.
<em>edited by Water baby on 01/06/2011</em>
Also, do NOT purchase anything without an IGI Certificate which is the international standard certification proving your stone is what it purports to be!
http://www.igiworldwide.com
I'm no diamond expert but that does sound like a retailer really really pushing their luck!!
This site is useful, although the stone I got was around 30% cheaper than this site is quoting.
www.info-diamond.com/others/diamond-prices.html