Best Buy is selling 4K Roku TVs through its Insignia brand online. Featuring the integrated Roku operating system with 4K streamed content from providers like Netflix, Amazon and UltraFlix, the TVs are expected to hit stores next month. The starting price for the 430inch 4K Insignia Roku TV is $399, followed by the 50-inch one for $499.99 and the 55-inch model for $649.99. All models have quad-core processors and 802.11ac dual-band WiFi. They can be controlled with the included remote or via Roku’s mobile app.