Missfiring with N62 4.4
 

I was looking at this car, 05 4.4 with about 70K miles, but having engine problem.
I went to take a look, found CEL is on with P0300, P0308 and pending P0306.
Not knowing much about N62, what could be the worst case scenario of this?
I assume easiest would be spark plugs + coils but don't think this is caused by bad coil in cylinder 8.