Anne Rogers wrote:

If the school is in an area where the majority of students couldn't
afford such a trip, then that's when you have to start appealing to
local companies etc. not expecting the few that can pay to pay for
everyone.

I doubt VERY much if we would have been allowed to do that at a public
school.

Why not? I read just today of a huge amount of money travelling between
a local company and the local school district,

State laws may vary, but corporate partnerships with
public schools are not uncommon. Not all corporate partners
are as generous, but most of the public schools around here
have some kind of relationship with a corporate partner.
That said, the nature of the partnerships differs quite a
bit, perhaps according to the needs of the school, perhaps
according to the preferences of the company.

Best wishes,
Ericka