Has anyone ever experimented with this? buying big concert tickets when they go on sale and then selling them for a greater price a week or so before the event?
don't do it a week or so before- do it when the hype is around. There's a concert in my area that you can buy the tickets (they sell out in 10 seconds, not exaggerating either) and then sell them right away for double the price- after that prices decline and rise a bit right before the concert. Its all about timing