U can go to these mythical "underground" markets, just go to your local sewer lid, lift it up and crawl down. Carry some boots, a tent, and some food, water, and clothes, might take a few days to find it. Watch out for those radioactive rats. I know its somewhere there... Last time I went there I found myself disected by aliens then given free VIP hacks in a 8GB flash disk.
The choice is yours.