sellers didn't realize that their used TVs had depreciated so much. New TV prices had gone down so much that the used sellers couldn't compete.
Anyway, you can get a lot of TV for cheap. Stay inside your constraints and do good research. Love the idea of last year's model. Don't fall for anything. Don't develop tastes that exceed your means.
Also, just buy a used TV from your parents. Start working on getting them to feel like they need to upgrade.