I've been trying to get a cheap OLED TV since I've got my PS5 on the Target deal and while I haven't found one just yet, I ended up finding this TV quite cheap.
It seems it is the cheapest 55" available right now after the quick research I've done, even cheaper than the Kogan ones.
I can't talk about the quality of this one in particular, but I have had a TCL tv in the bedroom for the past 3 years and it does the job, I'd definitely consider this one if I was after a budget TV, especially if it is the secondary TV.
By the way, I am still after a 65 OLED, I am considering the Hisense X8HAU just because it is the cheapest I could find, if you have any recommendations, I am happy to hear.
after reading your first line i thought it was an oled for $399 hahaha