My 17 year old has decided to get his girlfriend a diamond promise ring for Christmas. They have been dating a couple of years and she is a very sweet young lady, so I support him in buying this gift. However, I do not feel we should spend a huge amount of money for a promise ring. Where can I find a lovely promise ring of about .25 ctw without breaking my budget. I would like to keep this ring under $300 if at all possible.