Sure you can probably get a good value on a bluray player because people are getting rid of them still to go all streaming. But can you get a good price on a used working order 4K TV? Probably not. The prices of even used 2 generation old goods are going to be as high as they were when new before tariffs hit.
Used is not going to be cheaper in a week or a month or 3 months of tariffs, it's going to be the same amount as new right now or possibly more.
These days there are sooo many resellers, flippers, scalpers. People who think it's a side hustle to go around buying up cheap used stuff and selling it for just below the price of new stuff and pocketing the difference. It's become so hard. Late capitalism ruins even good deeds.