Yeah and using that money towards your computer is a hell of a lot less painful than giving her the diamand.
First off, if I give my gf a pretty ring, she'll not only be very happy, but there's likely to be a kiss in there somewhere (an' more...!).
Second off, I like making my GF happy, so buying her a ring would make me happy, and her happy, and there would be no pain involved.
Lastly, if I want to spend $1000 on my computer for playing games and crap, I can keep her from bang'n on it by giving her the ring. While she's all happy and occupied with the sparkly, she'll not be thinking about how much I "pyssed away" on my computer.