Most prison walls have a negative connotation. Money's walls have a positive connotation on the surface, at the beginning, but have negative effect eventually.
Anything that is addictive has this kind of an effect. When we start out with an addictive entity, we think we are completely in control--we'll talk about the prison of bad habits later--but then it ends up controlling us. Money is an addictive prison master. We end up liking our own prison master. That's even more dangerous than not believing that there are no prison walls.
Now, money itself is not bad. But the pursuit of money as the answer to your situation is evil. The love of money is evil. To give money the character of god is evil.
Did you know that money asks to be "loved?" It takes on personal qualities. We ought to love people and use money. Instead, we start loving money and using people.
To give money a personality is to make it a prison master.