It’s smart to consider buying a new air conditioning system when your old system is still working. You can get a few proposals without being under the gun of having no cool air due to a breakdown in the middle of summer.
A lot of people make the decision to buy when the compressor fails and needs to be replaced. At that time, the decision is to either buy a new compressor or buy a new air conditioning system with a full warranty. It makes a lot of sense to buy a new unit at this time.
A new system will carry a great warranty and will be more efficient than your old system.