I'm friends with this guy on fb that I grew up with way back when. After I moved out of the neighborhood we lost touch. He found me on fb we're buddies and his fiance friended me. I haven't talked to this guy in maybe 20-25 years. I'm assuming they didn't send out regular invitations to their wedding, I received an "event" invitation on fb. They have 3 kids together and 1 on the way. They're having a small ceremony at courthouse and then reception at their apt. They're not registered anywhere. I'm planning on showing up for maybe 15 minutes to give my congratulations. What would be a respectable gift? I don't want to seem cheap, but I barely know these people. Would $20 in a card be okay?