What's been your experience w/getting extra grad Tix?

I guess this sub will have to pin up a Grad Tix Megathread next year. So many people need extra tickets. Are you guys finding any? Are you getting them for free or what are you paying? $20/ticket? I know one person who paid money and got nothing back (scam). Seems like the ones most in demand are for the School of Engineering. Please share your experience, thanks