my audi a4 is up for 75,000 mile maintainence.. how can i get it serviced at a cheaper rate

This is a two sided coin for me. You have options, but as always pros and cons. A certified Audi dealer can obviously service the vehicle, but they often do run high in the dollar amount. Take into consideration though, that having the vehicle serviced by an authorized/certified Audi dealer, everything will be on record and you won't run into warranty/service issues down the road. Take it to a third party (Joe's garage), and you may receive the same service at a cheaper rate, but if he's not certified, he may not have the ability to submit the vehicle records into the system which may help you down the road with the sale of the vehicle and or warranty issues for example. I'm not saying one is better than the other, but just a few things to take into consideration when making your choice.