Trying to help out some elderly friends...

I know an elderly couple with a 2003 Merc Sable who I think are being set up to be totally ripped off. They tell me their car has been running rough. Even the old lady says, "It's missing." Now I don't have all the particulars of the engine, but it is a V6, the car may actually be an '02, but a tuneup cannot cost more than a couple hundred bucks, but they got an estimate of well into the three hundreds with the explanation that anytime the car gets a tuneup, a certain part must be replaced. They are not able to tell me what part this is. I'm guessing that this car, with less than 40K on it, could use some new plugs. What other tuneup parts are needed on this engine? Is it distributorless? Maybe wires, too. Could the mechanic be talking about the coilpack(s)? All speculation is welcome!! I'll be doing some searching now...

Well, after a little searching, this engine needs only a plug and wire changeout for a tuneup. I'm wondering if the coilpack is prone to failure and if it is routinely changed out at this mileage. Either way, this is not a $300+ job...

Nearly $800 later, courtesy of an AAMCO Auto shop, their car is running well again. Here is how it broke down (I may be a dollar or two off here and there):
plugs $60
wires $75
coil $75
valve cover gaskets $150
2 vacuum hoses $40
the rest was 4.5 hrs of labor $370

Total $770+. Total ripoff. I could have done the coil, plugs, and wires for them for the price of parts - well under $200. I'm sure the gaskets and vac hoses were unnecessary. The car only has 37,000 miles on it.