As has been mentioned, cost is all down to economy of scale.
Regarding “better” – use whichever you get on with best. Personally SPDs do awful things to my dodgy knees, so have been running ATACs for years.
I had a very old plastic set that refused to die and only went when the bike they were attached to was stolen. The more recent metal ones seemed a bit lower quality.
Currently running Roc ATACs which seem pretty good. Haven’t worn them out or managed to break them yet, despite many heavy pedal strikes on rocks.
Time cleats do need replacing every 12-18 months though, as they’re made of relatively soft brass. Not sure why this is, other than to provide a lucrative spares market for Time.