"meals out, theatre and museum trips and would he like to swap them for the Wii? He agreed that he wouldn't."
While theatre and museum visits are laudable, I can only imagine your DNs are in a significant minority, when given such a choice.
Or do you think it is that where they study, their peers, if they happen to have XBox PS2/ PS3 or Wii, simply don't brag about them but consider them "the norm" along with trips to the theatre or museums ?
As a teen and younger, I don't recall any trips to the theatre being of interest, not even to see a panto. There were infrequent trips into Brighton to see films but cash was always short (Mum had been widowed, and I was last of 5 children) but never a massive issue.
When I was at the boys grammar school, some lads went off on holidays to USA etc, another lived in a massive house in Brunswick Square, Hove (his room was big enough for full size snooker table, table-tennis table, piano, double bed, sofa and TV and windows big enough to walk through onto the balcony... take a look with Google Street View for an idea how big those houses are!).
Some had loads of cash, some far less, but even so we did compare what presents we had for Christmas, though of course in the early 70s the options were fewer and such costly items as laptops, XBoz, PS3, iPads, iPhones, etc., were far into the future at the time.