Actually, prices of TVs here are the same as they have always been because they use high quality materials and components. The Korean brands are often cheaper. This caused a lot of issues for Japanese brands in the West. They couldn’t compete with the cheaper offerings from Korea. This lead to them using cheaper and therfore worse components for TVs sold in the West, especially the US. Of course this also impacted the quality. Toshiba TVs sold in the West these days aren’t even sold here as they’re cheap Chinese sets using the Toshiba name.
It really is a shame but that’s what happens when you have strong competitors selling cheaper even if the product may not last that long.
So why have Korean products not taken off in Japan? Simply because people here don’t trust the build quality and know that Japanese brands are made to a high level (or at least the domestic products are). Same with cars. You’ll be hard pressed to find a Kia or Hyundai in Japan. You’ve got a much higher chance of seeing an American muscle car or an Italian super car.