Front pads usually wear about twice as fast as the rear pads, so if the rear are 35% worn or so as indicated by the tire shop, the fronts may have a descent amount of wear on them already. Only way to know is to take a look and measure.
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record