A good quality 1ct diamond is going to cost about $12,000...then you have to actually buy the ring, and have it set. Sure you can get one for like $700, but it'll be crap quality, and not worth it. Here is my advise...go for a smaller diamond but better quality...it'll look better. Also (and I"m one of those girls who loves her diamonds) even if you get your girlfriend a 1ct or 3/4 ct instead of a 3 carat...she's still going to love it. I promise...as long as you put time into choosing her ring. And if she doesn't...take it back and dump her. Upgrading later in life is good, too. Get a solitare now and then use the stone as a side stone later in a 3-stone ring (which are very popular now). Just my thinking...still love my diamonds, though. April baby