Upgrading my GPU, are these worth it?

I came across some second hand gpu's and I was wondering which one you would choose and why? Which one has the best value for money and is this a good idea in the first place?
My current pc consists of an 3700x cpu paired with a Gigabyte 1660 super gaming OC 6g. My psu is a be quiet pure power 11 600W 80 plus gold.

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Gigabyte GeForce RTX 2080 Super Windforce 8G - €275 (3 month warranty)
Gigabyte GeForce RTX 3060 Gaming OC 12G - €230 (3 month warranty)
OEM Nvidia GeForce RTX 3060 Ti - €200 (used for mining)
MSI GeForce RTX 3070 Gaming X Trio - €250 (used for mining)

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They all come from reputable sellers, the last two have been used for mining and both have some white oxidation. The seller says this won't affect the performance and could be cleaned with vinegar, is this true? This seller also offers to replace the thermal pads and/or clean the oxidation for an additional charge. If I would do this, what do you think should be the extra charge for new thermal pads? And could I clean them myself or should I let them do it. I obviously never cleaned my gpu with vinegar before (:

They all would be a masive upgrade in my system, but which one do you think would be best? Are these even compatible with the rest of my pc? Are they worth their price? I'm not looking into upgrading any other parts for now. I casually game (Fortnite, Sims 4 and F1) and use my pc for photo and video editing and graphic design. I am getting into 3d design using Blender, not professionally.