If you have the time I would just play ring games. Most of the time when we have private events here I will play ring games at the same time. If our event has a total payout of $100 I can earn that much in 30 minutes of ring games. The tourny ussally will at least take an hour. I have seen you play enough to know you can win in the rings. Just remember the #1 and #2 rules of rings.
Know your limit
Watch the table beofre siting. 3 rounds will ussally give you a good enough read on the players at the table.