Hi, the.mknabster, happy 2022 to you. I would say save the money if they are supposed to be the same performance. With T420 you can't find a new part almost zero to none chances are, I reckon.
I'm looking into purchasing a CPU upgrade for my T420, and I found which one I'm going to upgrade to. I'm looking online and there seems to be two extremes. eBay has a pair of CPUs for the same price as just one with an IT refurbished site. So my question is which would be better, spend the extra cash for something that has been tested, or save the money and buy used?
Buying a used/refurbished CPU