get the yankee hill machine phantom comp/brake. 22 bucks if you find it at a good place, and ive been using it for a year on 2 different rifles and it works great. not too loud, and it pushes the gun lightly into your shoulder, directly back.
What Mini do you have? If it's a Tactical, then you have a threaded muzzle, which opens the options up significantly.
If it's not a Tactical, then you have two options. Pin-on brake or have the barrel threaded. Threading the barrel is going to eat up your $50 budget in a hurry, and you still won't have bought a brake.
IMO, the Mo-Reaper is the best option out there, but the John Masen brake/flash hider seems to be a popular piece around here, as well.