I paid about the same from the Ford dealer here on 54. I've known the Service guys for a while and they took off stuff that Ford adds to pad the bill. Came out to around $400. The induction cleaning and fuel filter are what add a lot of time and labor. The flush is usually done by a machine while the mechanic takes a break.
I've had big time issues with TiresPlus when they fixed my wife's old car. They screwed up the brake system druing a routine fix, then charged me $400 to fix the vibration it caused. Totally misdiagnosed their own fault, and didn't care that I was charged to fix something that wasn't broken. I ended up filing a claim with BBB, but they didn't care (or respond to BBB). All their stores are independantly owned so there is no "next level" that you can take your claim to. If the local manager won't help you, then you're SOL. Just my experiance, but some people love the place.