Hunting
I'd like the ability to go out into Blaine County and hunt for different animals, deer, coyote, mountain lion etc. This would require you to purchase a hunting license and could possibly give you access to a hunting rifle or a specific knife to gut the animals. I think this would be great and would encourage people to explore outside of the city and allow civilians to purchase other types of vehicles, eg, Offroads/trucks instead of driving thier McLaren speedtails up Chiliad. This could also be classed a criminal act if you aren't in possession of the correct licenses etc.
Possible black market alternative: a shaman or a sketchy "natural foods" store somewhere that buys cougar spleen or boar's hoof for purposes best left a mystery. They could also purchase items from domesticated animals, both pet and farm.