It sounds crazy, but it worked for me. Most arenas take tickets at the main entrance, not actually going into the central arena area. For a sold out show I wanted to see (it was either Tool, or Bob Dylan. I can't remember) I got a job working concessions.
Then once the show was getting going, I told them I quit (Work concessions??!?! smurf dat noize!!!! I'm not selling giant pretzels with Tool playing 100 ft away) and walked into the arena area. I couldn't get down onto the floor, but I got down really close in the seating area. It worked out better than I even expected.
It's worth a shot, maybe.