Depends a lot on how much you pay for electricity I would have thought. The new ASICs like KNC's Titan offer a lot more KHS per $ for your initial investment, and a lot lower running costs in W/KH.
Speculating now: GPUs are a lot more flexible about what algo's they can mine, and most altcoins are as much about user numbers as they are total hash rate, so they will fork to algos which a lot of users can continue to mine with their GPUs rather than stay on Scrypt which will become dominated by a much smaller number of ASIC owners.
Sensible advice? Maybe you should consider investing the money elsewhere and diversifying your risk a bit