I use geekbench.com for comparing CPUs:
(The link is for single core performance results, there's a link on the page to multicore results.)
Mac mini (Late 2020) Apple M1 @ 3.2 GHz
Single core performance:
2355
Multi core performance:
8414
Mac mini (2023) Apple M2 @ 3.5 GHz
Single core performance:
2636
Multi core performance:
9760
The difference isn't very big.
Is this small percentage extra cpu power, most of it due to the 3.2/3.5 gHz difference, worth $70?
It's up to you.
I went from a M1 mini to a M2 mini and didn't notice much difference at all. Maybe a touch of extra snappiness overall, but no real difference in my cpu-demanding Pro Tools or Adobe apps.
The M2 Pro mini on the other hand, made a big difference; a couple of extra cores, allows for more ram, two more TB ports etc, but that's another story.