fak fak is right...you chose pretty much the best secondary seller.
You can check out your tickets, you know. Find any local Ticketmaster outlet, go in sometime when they are not terribly busy, and just ask them to scan the tickets for you.
I have sold extra tickets on StubHub over the years & they are very strict with sellers. They have seller's credit card, home address, etc. And the seller agreement is full of legal provisions that boil down to legal liability for any sellers trying anything out of line. The message is they expect sellers to be accurate and responsible--StubHub penalizes sellers for legal but annoying infractions like sending out tickets later than promised. I like selling there because it is less scary than talking to strangers and arranging meetings. And I've often bought tickets on StubHub--for the same reasons--and never had a problem with a ticket.
Craigslist is not so scary for selling Coldplay tickets, because Coldplay fans are so nice. I sold some tickets for this tour, and talked several times with my buyer so we could each be sure of each other, made sure they had my REAL name and my REAL phone number and even told them which night I was going to be at the concert and even what seats! Real buyers were clearly real fans (I had inquiries from obvious jerks that were probably working for one of the shadier resellers). And I made sure that they knew I was a real fan, too. I also found out that if you do a craigslist purchase and both parties are "Verified" on Paypal, both people get some protections through PayPal. (When you're "verified", PayPal has all that personal info that StubHub has, and so can "follow through" if there are problems at either end.) I've also sold on craigslist to teens--they were smart and brought a parent when we met. Don't let teens do "meet-up" purchases alone and make sure if they do online payments it's with something that has some security, like StubHub or verified paypal.
And if you totally end up buying tickets last-minute at the place--make the seller go to the ticket check-in with you! Learned that from friends who go to sporting events a lot.