Competing against your suppliers?

It's 9am and of the 4 calls I've taken this morning pricing tires, 3 have asked if I can match the internet price they're looking at. Take a 225/60R17 Yokohama TRZ: Tire Rack has it for $114 delivered....TireMonkey has it for $109 delivered....and my price is $101, or $108 when I've added the sales tax! It's a double whammy when you're competing against your suppliers and charging an additional tax that they don't have to pay.....