Cost for Head Gasket Repair? Recall Possibility?

I have a 2006 Ford 350 SuperDuty XLT 4WD with 80,000km (50,000 miles) and a blown head gasket. I'm near Toronto, Canada and the dealer is telling us that the repair is going to be a staggering $8,000 !! Parts are about $4k, and labour, at 35-40 hours, another $4k. I'm also reading on the net that this is a common problem. Does anyone know if this is a reasonable price for the repair, and whether there is someone reputable that can do it for less, and - wild shot here - considering that people tell me this is so common even on a low mileage vehicle, whether there is some general recall or class action lawsuit in the works?

Considering that we're talking about a truck and not a space shuttle, I find it difficult to use the words "reasonable repair cost" and $8,000 in one sentence.

thanks!