There is some good advice and some sketchy advice in this thread.
If you try to sell it to them for more than what you paid for it, they are going to win in court, easily, because you are trying to make money off of their trademark. Not only that, but you will probably also have to pay some of their legal fees. It used to be a common tactic against domain squatters, send them a letter saying they own the trademark and to stop using it, squatter says "Give me $500 and its a done deal", trademark owner takes it to a judge and has proof positive that you are trying to make money off of it.
Judge finds in the trademark owners favor, 9 times out of 10 they will ask for damages for legal fees, if you cant fly out to wherever the hearing is being held, which will cost you several hundred dollars at least, you get a default judgement against you, which will probably cost you thousands of dollars. Then you will freak out and have no way to pay, they will come after your bank account, even if you are a LLC, it doesn't really provide too much protection except as a tax entity. Ultimately if you cant pay your credit is fucked for years to come, all because you decided to hold on to a worthless .info domain name.
Id just drop it.