My tv is 1700€ , Headset: 260€ , Surround soundsystem: 2200€,
And ofcourse the extra controllers 70€ each, games 70€ each, decent hdmi cable: 100+
Ofcourse you don't need a surround if you wanna have headphones on.
And you sure can go as expensive as you want, but you also don't need a 3000€ PC and people still buy it.
Why? To get the best experience possible and I can tell you, since I got that sound system and that TV: movies, series , videos-games are so much better. It's unreal.