ChipFlip
One cent. That's the entire price difference between a used RTX 3060 Ti at $199.99 and a used RTX 3070 at $200.00 right now. When two cards from the same generation land on the same price, the usual "is it worth the upgrade" framing stops working. There's nothing to weigh. You just pick the better card.
The 3070 is the stronger card, and it isn't close
More CUDA cores, more memory bandwidth, higher power budget. The 3070 sits a real tier above the 3060 Ti in Nvidia's own Ampere stack, and benchmarks have reflected that since launch. At 1440p the gap is usually somewhere in the mid-teens percentage-wise, which is exactly the kind of margin you'd normally pay $75 to $100 for.
Paying nothing for it is unusual.
So why do they cost the same used?
Supply, mostly. Both cards shipped in enormous volume during the mining era and both landed on the secondhand market in enormous volume when that ended. The 3060 Ti was the more popular buy at retail, so there are simply more of them, and used pricing tends to compress toward whatever the market can absorb rather than tracking benchmark position.
The result is a temporary pricing quirk, not a permanent one. These two have traded places before.
The 8GB problem applies to both
Neither card gets you out of the 8GB VRAM conversation. Newer titles at 1440p with high textures will push past that on both, and no amount of core count fixes a memory ceiling. If you're buying either of these expecting to max settings for the next four years, adjust that expectation now.
That's an argument for spending more, not for picking between these two differently.
Bottom line
Buy the 3070. At a one cent difference there is no scenario where the 3060 Ti is the smarter purchase, and the only reason to walk away from both is if 8GB of VRAM is a dealbreaker for the resolution you play at.