So it's like doing local bitcoins trades for millions of dollars? If I were bob I wouldn't be comfortable with sending hundreds of coins in return for a suitcase full of funny money. How would he know if it's real money in the suitcase,or if it's funny money?
No. You go to a professional OTC broker who acts as the matchmaker and possibly the escrow too. There are plenty of them.
If I ever need to sell then that's straight where I'm heading. Sod exchanges.