For the equipment, I’d suggest having your students poke around their homes for any extra hubs/switches they’ve got. If your district happens to have some spares, ask for them as well.
And if all else fails, knock a few bucks off for bringing a switch or cable.
We did a LAN Party last year after hearing about others on CD. We held it in our School Library (~40 computers) and ran demo copies of Halo, CS, UT2K3, 1942. We also had 6 team members bring their X-Box’s and networked them together and set them up on Projectors in between the library “stacks”, to give it a “cave-like” atmosphere. We charged $20/person to play from 8 pm to 6 am and locked in those under 18. We sold pizza / nachos / candy / Rockstars / RedBulls. We cleared $1000 in profit in that one night. It was a huge hit, EXCEPT the Welchia worm hit a bunch of our school & district computers that same weekend by coincidence. Our district IT administrator said never will he allow us to do that again (even though we found proof in the logs, that it wasn’t our fault). We’ve been wanting to do another LAN party, but would have to use our personal computers and X-boxes - and we don’t have enough resources for that. And now there are 3 places in town where you can go pay to play network games. Ahh shucks!