I would learn to do it yourself. If you just want the shutter to work (and not be perfectly accurate at the listed speeds) it's not terribly difficult. You probably will break the first shutter you work on though, that's just the way it works.

Most of the time fixing shutters just involves opening it up, taking the timing gears out and soaking them in lighter fluid and putting the gears back in. If you can't take the gears out open it up and squirt lighter fluid in there and let it evaporate out. Add a tiny bit of oil to the gears after soaking if you want.