It's taken me 3 months to mine 1 BTC with a 7950, but I mined altcoins and sold them, not bitcoins. Mining bitcoin straight, I probably would never reach 1 the way the difficulty is currently.
What type of alt coing did / are you mining. As far as my rig would go, it would be the cheap kind that with time can et to the quivelat of what you got. Using USB block eruptors in hubs... sill trying to work out my setup thouh. I'm not expecting thigns to go fast, I just wana do something that works and sort of pays off in the end.
From what I can tell, a USB eruptor rig can be used to mine other alt coins like BTC so long as they use tthat 256 sha or whatever it is.