Re: Putting on a great light/video show on a low budget?
Second on having someone else to do it for you.
I have seen guys wire up floor switches and use coloured spot lights (like the ones you put outside at x-mas) then make the odd lighting change here and there, but never been to impressed other than the fact that the band took the time to at least try. I've seen a few bands bring LCD projectors as well, can run a dvd of whatever you like as the backdrop.
I saw Tool in '93, second stage @ Lollapalooza, they played during the day, no lights, just rock. Best mosh pit I've ever been in.