Volvo: Volvo door wont open, assembly shop, shop time

Question
Passenger door on my 1980 Volvo won't open from either side - actually every once in a while it does open.
I tried spraying some stuff from Kragen on the lock mechanism, but that did not help.
Is there anything I [a non-mechanic] can do myself? If not, what kind of place should I take it to. The dealer is usually very expensive. Thanks.

Answer
Laurie,
Look for a shop that works on Volvo's and take the car to them. They will have to remove the door panel to inspect the inner linkage of the lock assembly. Shop time is per hour so you are looking at about 1 to 2 hours of work. Plus any parts if needed.