Pills, bribing NPC guards, buying VCE tools (aka buy a crowbar, you can use it to open boxes for that one turn), soda machines, etc
There should be threat levels. If the prisoners go past a certain point, an automatic alarm sounds and guards get better weapons. Guards aren't constantly armed to the teeth, they get
Progressively more armed as the prison loses order.
Limit the armory to only supply weapons appropriate to the threat level. Pistols in area 1,
Shotgun in 2, SMG in the court yard, rifles if they escape the main court yard
Make it an ESCAPE, not a Sunday stroll. How do they escape? Are there MULTIPLE ways to escape? You sneak into a shipping container at a nearby dock!
You catch a ride on a train going through the woods! You bribe a guard to get you an escape driver! Stuff like that.
Make it so players drop items when they die. If a prisoner kills a guard with an SMGS and shotgun, they will take the weapons in a prison. So don't die or you forget over your allies.