When I got to Bannack and found a spot to set up camp, a fellow biker, with a Triumph Tiger, walked up and asked if I wanted to share a camp site with him so we could split the $18 camp fee ($28 for him since he had out of state plates.) I said sure, because a $9 campsite is much better than a $18 site. 
We traded moto adventure stories and then explored Bannack the next morning, before splitting off again...