Amazon has some "Prime Exclusive" deals on two of its Fire TV Edition-branded televisions: one a 50" 4K unit from Insignia, and the other a 43" 1080p one from Toshiba. Both are discounted by $100, which means sales prices of $249.99 for the Insignia and $179.99 for the Toshiba.
These TVs were both released in 2020. The Insignia is equipped with a 50" 4K display, HDR capability, DTS Studio Sound, and Fire TV functionality built in. Meanwhile, for $70 less, the Toshiba has a 43" 1080p display, DTS TruSurround, and Fire TV built-in. I'd argue that the Insignia is the much better deal here, but both the Insignia's $249.99 and the Toshiba's $179.99 represent all-time low prices.
Both deals are available only to Prime members, and they're set to expire in around 140 hours (five days and 20 hours) as of publishing time. Shipping is free; see the links below to pick one up.