Botball is a great program - our team started with that last year. We competed against other middle and high school teams. I don't know how expensive FLL is, but Botball wasn't impossible to fund.
Sounds like, in your situation, Botball would be a good option. It's not difficult to compete (you need some legos) and we had a lot of fun.
The programming, although it is C-based, is not that difficult - and that's coming from me, and I'm not a programmer.
