Buy whichever one is cheaper on a given day. That's the honest answer here, because the performance gap between these two chips is small enough that it shouldn't be the deciding factor at all.

The numbers don't support a real preference

Used, the 14600K runs $14.99 more than the 13600K on ChipFlip's tracked listings, under a 7% premium. PC Guide's own comparison found the 14600K ahead by about 3% in aggregate benchmarks, with boost clocks nudged up slightly (5.30GHz versus 5.10GHz on the P-cores). In gaming specifically, the difference mostly disappears, since the GPU is the actual bottleneck in nearly every title tested. A few FPS here or there, nothing that changes how a game feels to play.

Why this is a real refresh, not a fake one

Intel didn't rename the same silicon and call it new. The 14600K genuinely clocks a bit higher and posts real, if small, gains across the board. It's not nothing. It's just not enough to build a purchase decision around when the price premium exists at all.

What actually should decide this

Whichever chip is cheaper at the moment of purchase, plus whatever the seller's listing condition and included cooler situation looks like. Neither factor has anything to do with the CPU model number, and both matter more here than a 3% aggregate benchmark spread.

The takeaway

Don't pay a premium for the 14600K over the 13600K based on performance alone, the gap is too small to justify it on its own. If the two are priced close, the 14600K's marginally higher clocks make it the tiebreaker. If the 13600K is meaningfully cheaper, take it without hesitation.