My wife and I felt the same way too, until we actually compared them. The sparkle and brilliance in the diamond was dramatically better than any other stone we compared it to. We went into ring shopping pretty determined to not get a diamond, and yet still bought one.
Lab diamonds aren't really cheaper than natural unless you are talking about pure shit quality or really tiny ones.
I think the biggest problem is that most people have not seen moissanite in person, and don't realize that it can compare very favorably (if not more so) to a diamond. Glad to say I've managed to sway a couple of my friends so far on that front ;) Here's some pics: https://www.flickr.com/photos/chix0r/sets/72157637715040063
Personally I think a synthetic diamond is better than a natural one, but IFLS.
There are NOT noticeable differences between a $30k diamond and a $3k moissanite stone. A better analogy would be $100 "professional HDMI cable" and a $10 standard HDMI cable.