Coil #3 Failed - Replace All or Replace One?

[surfajl77]

Note: 2009 Yaris is currently at 408K.

After my last episode on 10/21 where my alternator failed and left me stranded until a tow arrived 4.5 hours later, I was faced with yet another issue last night that left me in a similar situation.

On the way home from work, the engine started jerking and misfiring, so I immediately put on the hazards and was able to get off of the road and pull into a a nearby Starbucks. I had this happen to me a couple of years ago, which ended up being a failure of coil #2 - so I suspected a similar diagnosis. I requested to be towed to the Firestone near my house.

They called me and confirmed that it was indeed a coil failure, this time #3. However, unlike the last time this happened, back when my car was in the high 200s, they are now recommending that all four coils be replaced due to a risk of the others also failing.

Am I being ripped off? I mean, the amount of time between this coil failing and the previous coil failing is like....four years.