My son has just gone into year 8 but back in March he came home with a letter for a trip to germany this november for 4 nights the cost would be �165 which included my son being added to a group passport rather then having to get one. It is a lot of money especially for a single mum but I did think that was quite reasonable, I spoke to my mum & she offered to help me with half the fare, but when I sat my lad down & explained to him his spending money would also be a christmas present, he soon decided they he didn't really want to go that badly after all.
I do think 10 is far to young to go to France, the furthest I ever remember our school trips going, which I never went to, was hydrians wall.