Sometime in the next few months I plan on proposing to my girlfriend.  I have done a lot of research and reading about engagement rings and have met with a local jeweler a couple of times.  The price that I have been quoted for the ring we designed seems a bit high to me, and I am trying to determine if I am being overcharged, and/or if there is any room for me to negotiate on the price.   The design I have decided upon will be an 18k yellow gold shank with a...