Yes, they can be a hundred times faster so now it's only 273,378,930,384,066,111,944,300,099,749,229,403,236,110,674,297,569,624,874,932 years.
More seriously, GPUs are faster because they are highly parallel, and parallelism can only give you a speedup that is linear with the number of processing units. So unless you're planning to build a GPU with trillions units, that won't help much.
A farm of a billion GPUs, each with a thousand cores sounds quite feasible with today's tech and gets you to trillion-times speedup of brute force. So, feel free to divide by 10^12... still not tractable.
I was in the market for a single GPU about 6 months ago, it shipped in a week and didn't break the bank. Buying a billion GPUs is an entirely different question. I'd look into buying fab equipment and doing a custom architecture. Given the length of the computation we're talking about, even a decade of lead time wouldn't significant. But as I understand it, current lead times are still less than a year.
More seriously, GPUs are faster because they are highly parallel, and parallelism can only give you a speedup that is linear with the number of processing units. So unless you're planning to build a GPU with trillions units, that won't help much.