I bought my fiancee's engagement ring at Mon Ami, and we got her and my wedding bands there too. The craftsmanship and quality are amazing, and it is impossible to beat their prices. My fiancee's engagement ring was custom made. The owner, Anand Sheth, helped me pick out the diamond, and he worked with me to design the ring and wedding band so that they would both have the same patterns of diamonds and sapphires. The rings are absolutely gorgeous.
The bottom line -- if you are even thinking about getting a piece of custom-made jewelry, talk to Mon Ami first. I guarantee they will make you a better piece than anywhere else, and they will have the best prices too.