Not to mention Brewman's hops. Go Steve.The serve by the glass systems I have looked at use Argon to both dispense and prevent oxidisation.
CO2 would help displace O2, but it's very soluble and will affect the pH of the wine causing flavour changes - probably fine for a couple of days at home - not really an acceptable option for a bottle of Grange that might be sitting for weeks.
If you kept CO2 overpressure on cold wine for any length of time it would take up a lot get some fizz and taste very different.
Nitrogen is widely used in packaging, mostly because equipment that de-oxygenates air has become very inexpensive (in commercial terms). Even biscuits and potato chips are MAP (Modified Atmosphere Packaged) to retain freshness.
seems to beSunnyvale Fruity Lexia Cask 4L
Dan Murphy case of 4 $20.99 is this the correct price.