I just paid $556.00 to have the spark plugs changed in my 2006 5.4 and that was with 5 broken plugs. No extra charge for the broken ones. So that was a decent price all things considered. I took it out on the road for about 10 minutes and now it's running like a champ. The stutter I was having at around 45-50mph is gone. It was an independent shop and the customer service at this place was outstanding. Very satisfied with the whole experience. If anyone is in the Central Florida looking to have this done, PM me and I'll give you the shops info.