Another way, less stealthy, find a known location where anyone can meet to buy Bitcoins with cash in person. No meeting in random spots down dark alleys at midnight but there should be a Bitcoin coffeshop or I should be able to go to any Starbucks with cash and get Bitcoins.
Now here is the problem with Cash, with Cash you gotta worry about getting killed for it, or beaten up and robbed when it's a big enough amount. Bitcoins aren't cheap anymore, they are $100+ a coin now so now it's in the dangerous territory that drugs inhabit of being just cheap enough where people can afford it but just expensive enough that people will rob each other over it. These dangers exist primarily for the buyer not the seller imo.