Diamond Candles makes candles (duh) with embedded diamonds (du...really?) Each candle is guaranteed to contain a sparkly ring for its burner to discover as the wax diminishes. Granted, they're not all diamonds, and they're not all set with real stones, but...some of them are. The themed candles can reveal anything from gumball machine trinkets to prized gems, with rings valued at $10, $100, $1,000, or $5,000.
Diamond Candles themselves rotate in available scents and artwork, and ring acquisition takes about 10 to 15 hours of illumination time, except for those who insist upon instant gratification and dig through the soy-based medium with a spoon to uncover their prize immediately. Obviously the vast majority of candle rings will rate in the $10 price range, but should a lucky lady get one with a 14k symbol inside its band, she should take it to a jeweler for a verbal appraisal, and plan to wear an ear-to-finger grin for the foreseeable future.
Included rings are protected from the candles' wax and heat with a plastic bag and gold foil wrapping.
So I think a good idea for men who aren't sure they want to marry their girlfriends would be to buy a Diamond Candle and make a deal: if the wax burns down and reveals a ring worth $1,000 or more, they'll consider it a sign they should get engaged (and poof! there's your engagement ring for $24.95). However, if the wax melts down to a $10 or $100 ring, it's a sign the girlfriend should stop hinting, pestering, and badgering him about marriage, and just enjoy her cheap consolation prize. It's still shiny, baby.