diamonds are a scam, pure and simple (money wise). Between the DeBeers diamond cartel, child labor in Third World diamond processing/cutting operations, and blood diamonds/conflict diamonds? used to finance oppression and genocide in Third World African countries, diamonds are just not worth the hassle, guilt, inevitable depreciation, and, let's not forget, thousands upon thousands of questionably spent dollars. (Politics aside)....
...if it were me i would sink my money into Moissanite (looks better than a diamond anyway and runs about $500.00 a carat, or better yet (Tanzanite..at least then you investment would appreciate in value)