Amazon has the TCL 49S405 49" 4K TV for $270 with free shipping.
Note, this is the 2017 version. But at this price, it is a great secondary or tertiary TV. I have owned a 2017 TCL and I can vouch for their quality. To me it is the best "cheap" brand TV, much better than Vizio.
Update: I confused this S series with the P series. This S series does indeed have HDR in the form of HDR 10 (not the superior Dolby Vision).