You've already been told by a repair person that it's not worth repairing. They may be right at shop prices but if you supply the labor it might be different. You have nothing to lose by opening it up and seeing what's inside. What is the machine doing or not doing that prompted you to take it in? Did the repair person say what was wrong or just that it's not worth trying to repair? I probably wouldn't fool with it if the gears are shot but if it's something minor that's different.
Rodney