a decent 630 Mhash/s on my sapphire 5970, expecting to break 1 Ghash/s when my second one arrives

....every time I see those 2-3 Ghashers in my mining team it makes me feel small, and I long for even more power. If I wanna go further I think Im gonna have to slap together a dedicated rig. Right now its a gaming rig used for mining, not the other way around. Thats when I feel like it goes beyond a hobby into an investment, and ROI is not great for BTC mining right?