Gotcha! Ok yeah, if the card is used that is something else. Most of the time they(SMD's) have gone through a 'phase' as they say. And the one you get is not a 3070 or higher, I think you are fine (and if the price is good). And you know, the 3060 is just a failed 3070-wannabee That's how it works.
Just keep in mind that Gigabyte AND Inno3D are the worst on the market. The components used, they rather don't spend an extra dime for/on it. While others are, and we talk about a few cents here and there, and not dollars. Cheap bastards, and Inno3D makes those, that you sure can forget their support.
Yes, please have your eyes on a 75Hz or 120Hz monitor at least. And what resolution you like. I bought my monitor for a good price(100) and that is an 144Hz one, but still on 1920x1080 for myself. And yeap, my eyes are getting old too. I just hate to squeeze my eyes, lol.
Once you install the 3060, let us know. Besure that you run something like 3DMark(can be used for free) and with a backplate, you can feel how hot it gets. Like @KaptCrunch mentioned, keep them cool!