Servicing costs between dealerships

Need your help...

I have a 1999 Civic Coupe which is due for its 80,000km service. I rang around our four local Honda dealerships to get quotes and the price differences were staggering between them.

South - $875
North - $690
West - $850
City - $915

All except North include overhaul of the brake master cylinder, which they state is part of the standard log book service schedule. North states that it is NOT part of the standard service schedule. Who do I believe?? Why are the prices so different and work performed different when it should be all standard across Honda dealerships and what should be a standard schedule which is adhered to?? Of course North is cheapest and the most tempting but why would they omit work on the brake master cylinder if the others claim it is part of the service?? Help please...I'm not sure what to do and who to believe!

check ur manual... if the overhauling is not stated in the log book... then it shouldn't be required... but i see dealers(non-honda) trying to convince customers to do extra stuffs so they can just simply charge more on larbors
the differences in prices are most like to be labour cost differences...
u can try to save up a bit my preparing parts urself... eg oil, oil filter etc...