The air conditioning is broken. Should I invest a large sum of money to fix it?
A/C is a luxury. How much do you want that luxury? What is actually broke, and the overall condition of car is whether its worth it, or not.
Seen it done many times.
That depends on the overall condition of the vehicle, how much you like it, how long you plan to keep it, what your budget is, and where you live. In Minnesota I’d leave it broken. In Miami I’d fix it…if the other conditions justified it.