96 stratus...popcorn machine?

the treads that hold in the spark plug on my 96 stratus has stripped. someone advise me to use a helicoil but the hole that houses the spark plug is too small to fit for the tool. a dealer said i would need a new head, but cost more then the worth of the car! can anyone help?!?

i'm young and unexperienced but i'd retap the treads and put in a new spark plug buying a tap is a lot cheaper then replacing the head.

but you might want a second opinion from the other guys around here
its only a few bucks