May be a simple leak and add some freon.
I know someone who was having problems with a used German car (top of the line brand) with compressor leaks or or evaporator. The part and install were something like $1,500.
I suggested one of those leak sealing kits. There are a few of them out there. Some are better than others.
Anyway - they had the mechanic put the stuff in and it has been fine for 6 + months.
What he said. All of the symptoms indicate a freon leak. Also, an AC system should last more than 12 years. I’d do the cheapest thing first and not assume that you have a major problem. Get at least three reputable opinions.