Spark Plug Questions
The $300 is worth spending to take it to the dealer that knows what they're doing. Taking it to a shop that may not know how to get them out if they break is going to cost you a hell of a lot more in the long run (having to remove heads, re-tapping the threaded hole, a plug blowing out, etc). Just take the advice and get them done right... else why ask for advice if you're going to do it whatever way you want to anyway?

