OK, so Sainsbury's had their turn last week with the PS4 price glitch.
It seems the group haven't learned much in a week.
Possible pricing/description error which makes reference to both 500gb and 1tb versions.
Who knows, maybe they will honour this one? After all it is reduced from £319.99 which would seem in line for a 1tb?
Also note that I found this in see all prices cuts>technology>games and consoles>xbox one>consoles.
Also note that the fifa version (1tb) has the same rrp of £319.99 with only a £20 reduction whereas this shows as £70 off.http://www.argos.co.uk/static/Product/partNumber/5729771.htm
It could be a genuine reduction.
Don't shoot the messenger!