I have seen a few serious competitions where points are awarded for different things and the "total" is what wins at the end of the day.
So instead of having a budget limit, frag limit, etc.
What about 0-10 points being awarded for each of "budget, aquascape, coral/livestock, equipment design and originality".
That way, if you spend more, you might get nice colonies, but you'll lose points for being more expensive. This way you would get a balance between how nice a tank looks, and the expense for it. It seems most of the debate on the budget stuff is about bang-for-buck. This way everyone gets to play. I would rather attempt to do a tank for a few hundred and see how much/nice I can get it. But, I don't want to go head to head with someone that just blew $3000 on a 33 gal tank. Of course it will look better. I think the contest should partially about "bank-for-buck", but spend whatever you want.
With that being said, my artistic talent are horrible. And I think it should only be fair that those that have an imagination get "points" for it as well.
There, that is my "morning, and coffee hasn't kicked in yet" rant
