I have a former coaching client who came up with a cool idea. She suggested that I create a pricing challenge with this community. I'd create a fictional (or maybe even a real) scenario, throw it out to this group, and see who gets closest to that price.
It wouldn't be reward-based since we all can come up with a price and we all could be correct provided the price is profitable. But this way we could work through a price together and see how we each do things differently based on our pricing strategy.