I think most of the time people feel a $69.90 Brake job is all they need. Very seldom that is true. Once you pull the wheels off and start inspecting, the price starts to go up.
The things Brake mechanics look for are rotor and drum thickness, shoes, pads, hardware, springs and lines and calipers etc. I used to give people 2 estimates. One is what they can get by on and another one is what it would take to get their brakes back up to 100%. This is not only right but should be performed with every brake repair estimate in my opinion.
I think the $69.90 jobs only applied to the newer cars. The older cars with over 50,000 miles on them seemed to get higher and higher. Thats when parts start to leak and rust. So be prepared for a higher estimate if you own an older vehicle.