Lincoln/Mercury Repair: 97 Lincoln Continental, poor gas mileage, advance auto parts

Question
I have 95,000 miles on my 97 continental.  It's time for a tune-up very poor gas mileage and I've been told to expect to pay at least $500.00 The wires and plugs being the most expensive.  Can you offer any advice on possibly getting internet parts for cheaper or any other suggestions? Already new alternator, starter, battery.

Answer
hello marcia
thire is a lot cheaper parts and what they are telling you call advance auto parts a set of good wires is 21 dollors life time warnetee and plugs are a dollor a pice. Or advance auto parts would have them parts for the same amount good luck to u if you need more help let me know pete