I see some normal people on craigslist selling tickets... sure plenty of scams and do your due diligence, but one girl is offering to pick tickets up at will call with you for Friday, so that's impossible to fake. She may not show up, but you don't pay before you get there.
Just saying, I know people are out there to screw you, but I sold 2 tickets this way so there are more like me and you... you can almost read the ads and see the difference between human being fan and scammer. Not always.
Just saying. If you meet the person at their midtown office in a suit, most likely not selling you fake tickets. They may be trying to make a buck or can't go.
I think it's more likely to get real tickets from craiglists than from people around MSG. Now that's not the first option. Just saying. There are still good people and real tickets out there.
Some old people (like 40 and above) don't know what the hell resale is or stub hub... or they don't trust it. So they sell it for cash like old days.