A small group of men stares intensely at something. Coming nearer, you see puppies, obviously still young, as they are small and only learn to walk. Cute as they are, the men look serious and exchange a comment here and there, making their mother nervous. But one man keeps her somewhat calm, while looking with others on the little ones.
The puppies are a completely new dog breed. The breeder hopes for better characteristics, the other men are mostly hunters and other dog-fanciers, that were called or came from own interest. If all looks well, they will have business. But now, they are just watching.
You realize a group of men is going right to you. The man in front has a hard determined look on his face, the two men behind follow him with some uneasiness. He stops before you, holding the handle of his sword in one hand, and slaps (choose person carefully) with leather gloves he carries in the other hand. "Rhadagald Thinvoice, I challenge You to a duel to dea..." Stopping abruptly, he realizes this is the wrong person.
"Ladies and Gentlemen of Worth, please come closer and have a look... " In a little stand with numerous maps, the human Advantos sells land-rights with a shining smile and jovial talk at bargain prices. He sells even squatter rights (first to settle is the owner). About 20% of the lands do not exist or belong to someone else. About 30% do not have even that value, or have other problems attached- swampy, cursed, haunted, Old Indian/Pet Cemetery (tm)... Be assured you will not see this man in the same city twice.
A few musicians play their instruments and a beatiful maiden dances to the music. Wonderful to look upon, you surely will spend a few coppers, will you? In addition, two thieves move through the on-looking crowd. "Spare the coppers - loose the silvers!" your father used to say.
Animals have parasites and diseases, so do plants, there are even bacteria that cann dissolve oil spills or plastic or what have you - why couldn't there be a disease living off magic - a magic item could be infected, losing power and speading the plague to other equipment it contacts, while a magic user would slowly lose his powers and contaminate all he works with or casts a spell at...