I was told my air conditioning seal is leaking. Can this be fixed inexpensively?

we'll need to know what seal. no matter what you'll have to have the system recharged. what type of car?

It can depends on were the leak is. You will have evacuate the system fix leak may be a hose a core or even seals in the compressor. You will need to replace your dryer and condenser before you charge the system up. Not easy but can be done yourself if your an average Mech.

im not sure the model care but the most common seal leaks are just o-rings that are dried out but in some cases it is the front seal of the compressor which is a costly fix , but any a/c specialist can diagnose it easily.