You started the thread with "My head gasket blew". Is that what you've determined or what they told you the problem was?
There are test kits available to determine if you have a blown headgasket. A P0306 is misfire on #6 which is the most common failure point on a blown headgasket. Is there milkshake in the oil? Does your coolant look cloudy? Is the engine overheating?
I pulled my engine in July 2021 and took it to my local machine shop. I spent $800 on the LCEngineering kit, supplemented about $500 in OEM parts, and paid about $1300 in labor. Removal and installation wasn't easy and we discovered issues along the way but all in all I spent way less than $3000 for a full rebuild.
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