Call up Val Surf in Valley Village. They guy that works the ski dept is amazing. They gave my skis the best tuning they have ever had and that says a lot since I work at Footloose which is the best overall ski shop. I'm not sure how much they charge cause I got it done free, but they are usually pretty resonable with everything else.
Another place to check out is the Sportchalet on Foothill in La Canada. It is the origional sport chalet and lacks the big box feels of the rest. They had a skiing only shop but it burned down. Also it is only $20 there.
Chicks in Pasadena has the best ski repair dept out of all the chicks around.
Then there is that shop in Newport Beach. I cannot remember the name of it for the life of me but they only sell ski equipt and golf equipt. It is on the PCH on the east side of the street. It is really close to the misplaced taco bell and that really amazing thai restaurant. they probably cost a lot though.