re: Engagment Ring $

I purchased the stone that I wanted from a estate sale and saved quite a bit even over all of the sites mentioned in the thread. Was able to get a 2.2 carat stone with high quality parameters for $8300.
So my two cents are look for estate sales or people who buy "dead people's" stones and see if you can't find a real deal over the traditional brick and mortar sellers or the blue niles of the world. And also don't buy anything until you can pay cash. Debt is not good at all and paying cash teaches you to value your money more.