I see no problem advertising a local's discount as they are the people who will most frequent the service. It could be marketed in a much better fashion though.
Locals disount is a huge factor in seasonal towns..In Moab winter was quiet, in Red Lodge, we had 2 shoulder seasons, between the Ski Hill closing and the pass to Yellowstone opening.
GM pays warranty based on the average cost of labor on a sample of 30 consecutive Repair Orders.....
My solution...a high labor cost for the area, which would still look low for a visitor from a Metro Area, and a locals discount card, that gave 20% off "cash " kobs, but still got me a decent rate for warranty work!
Advertise Full Price, then give a locals discount.
How would you determine "locals" .....in San Pedro its pretty easy..if I dial a 7 digit number and that phone in your hand rihgs....discount
If it takes a 001 and then 10 digits....big bucks for the taxi man