Well I've only ever done JFLL before... It's cheaper, but a little more weighted toward "cute" and away from "challenging", especially at the higher ends of the age range. Not bad, just lighter. We did that with a four-boy team last year and had a lot of fun. The kit was about $100 and we shared the cost and then re-sold it at the end and shared the earnings, so it came out even.
This year we're proposing to do the FLL level, but from what I can tell four kids isn't enough (just workload-wise), so we're looking to add some. I think 8 seems about right... So the $200 registration and $65 setup kit will be split 8 ways (if I can pin down 8 people!) which isn't so bad. The official Mindstorms kit is $315 I think, and I'm guessing it has extra parts, although it is SO HARD to figure those things out from the website!! grrr... Anyway. I'm hoping we can make it on the retail version of NXT plus what we already own, but that means we're depending on two families' personal Legos (mine and one other) for our team use. On the plus side, we don't have to buy more for the team, and we don't have to figure out how to divvy them up at the end. On the minus side, parts could be lost. I'm completely OCD about that, and will be inventory-ing regularly, but it does make me nervous. I hate lost parts.
So our own financial outlay will be to buy our own Mindstorms kit (which I'd be doing anyway), and 1/8 of the registration and setup, which comes to about $33. Not too bad.
Take all this with a grain of salt though... I'm only starting out with the FLL level!
