Don't play. If you must buy in for $120. Yes, you are playing with 40bb. It's not always a fold/shove situation. You can take 1/5 of your stake with AK, AQ, KK, QQ. Those hands you want to see the flop against 1 or 2 players. But if you play tight, you can do an all-in squeeze play and pick up small pots in late position. If you do get called holding a decent pair like 8's or 9's, go ALL-IN. If you get get 3 callers. Well, you're getting 3:1 on your money for the main pot. Most hand ranges that will call your are either a bigger pair(which you're a big underdog at 4:1), or AK, AQ, AJ, KQ, A10
In that situation, when 2 or more players have an any two cards from A to 10, you're pretty sure you won't lose to a straight. They have each other's outs, for ****'s sake. Unless the case Aces pops up, you're middle pair will stand up more of often than not.
Lets say you do triple up with 9's by going all-in. Count your chips, tip the dealer, and stand up. You need to quit while you're ahead.