If you are going to atempt the job it will save you a few hundred. You should only need to replace the Plugs, but if you want to replace the Plug Boots you can. The coils I wouldn't worry about changing since the vehicle runs just fine with no problems. The Boots will cost about $8 or so each the Coils are about $60 or so each and the plug are about $8 or so each. And that is what you would pay over the counter at a parts store. And since the quote the garage gave you was $450 they are most likely just doing the Plugs and Boots and that sounds about right for the job. The plugs throught the garage will run you $12 - $16 each and about the same for the Boots.
So, if you do the job as you can see you will save.
This is what the Coil Over looks like and they are pretty easy to remove to replace the plugs and boots. There is only one bolt holding it in place...
Tuesday, June 23rd, 2009 AT 8:25 PM