The synchro honestly is not worth fixing. You'll have to remove the tranny, and basically completely disassemble it. If you have the knowledge, ability and equipment to do it, then it might be worth it. But any honest mechanic will tell you to live with it until more problems show up then simply replace the tranny. It is not cost effective to pay someone to do it. If it's worth a weekend of your time to do it, then go for it.