electronic_express via eBay has the TCL 55" R617 Roku 4K TV for $629.99. Coupon code PICKFAST brings the price down to $535.49, an all-time low. Note that you must check out via the eBay app to use the coupon. No tax outside of Tennessee and Alabama.
https://www.ebay.com/itm/TCL-55-4…3059484745
Other sellers on eBay have this same model at the same price in case the above listing sells out or charges tax in your state.
wholesale_connection (99.3%): https://www.ebay.com/itm/TCL-55-i…2547650267
dealonline18 (99.2%): https://www.ebay.com/itm/TCL-6-Se…3063064426
Note that coupon code expires at 8 PM ET!