I'm still not quite convinced. Dying Light, another upcoming next-gen only game (made in Poland), also points at i5-2500 as a minimum CPU to run it. And according to CPUBOSS, i5-2500 is on par with my 3450... And frankly, I don't want to barely meet Witcher's minimum, especially if I buy a high end graphics card.
We don't know what the minimum is, though. We don't even know that the CPU will be carrying a heavy compute load. It may just be pushing data between RAM and the GPU. A Sandy Bridge does that as well or better than any later CPU. And games aren't written to take advantage of large numbers of hyperthreaded cores.
In the end, it's your money, not mine. But I cannot tell you to spend it on what more years of experience than most of the forum members have been alive tell me would be a waste.