Fifteen or so years ago I was the only one of my friends not to go on the school ski trip, and also one of only a small group not to go on the German exchange, both because my mum couldn't afford it.
It was a really big deal for me at the time. I understood why I couldn't go as I understood that my mum didn't have the money, but that wasn't really the problem. The main issue was that it was more fuel for the playground bullies who already enjoyed singling me out as my trainers/ schoolbag/ coat weren't the right brand.
I think that such trips really single out the poorer kids from those who are well off. Yes, children have to learn that not everyone can have the latest Merc or whatever, but this is different. We're not talking about the thousands of pounds that fancy cars cost, we're talking about a few hundreds of pounds for a school trip. The majority of kids will go, leaving the same ones behind every time.
As a teenager, being singled out for being poor is a big deal, and a week's holiday with your mates is a HUGE deal. Being the one who can't go - and who misses out on the in-jokes and gossip for months afterwards - is really upsetting.
I firmly believe that the kids from better-off backgrounds will already have the opportunities to go on expensive holidays outside of school. Certainly my friends who went on the ski trips etc were the same ones who were taken to the likes of Orlando during the summer.
What's wrong with keeping school trips to affordable foreign exchanges or outdoor pursuit-type holidays in the UK, with subsidised places for those on free school meals or whose parents wouldn't otherwise be able to afford it?
In many cases, it will be the kids from poorer backgrounds who will get the most out of these trips as they are the ones who perhaps otherwise wouldn't go away at all.