fpv goggles resolution

So I've been reading a lot on fpv goggles and camera resolutions...perhaps too much. Head...hurting..... I see 640x480 goggles that are $250+, all the way down to the HK/Turnigy 'Basic' goggles at 428x240 (Widescreen) for $90 bucks. The problem is that most forums online say you want at least...