how do you deal with a local transaction with a large sum of cash?

Man, I guess I've just been lucky.... I've bought plenty of high dollar items and sold plenty of high dollar items on places liek Craigslist. We jsut find a place to meet up (sometimes their place, sometimes a parkinglot, sometimes a Starbucks), they hand me the cash, I hand them the gear. All is good. If it's a starbucks, I might even stay and have a cup of joe.

Same here. I guess I've been lucky as well. You do hear of horror stories from time to time. Just plain old common sense will usually keep you safe