Spark plug was smashed after being hit by a piston - does this require an entire engine rebuild?

I have a 2011 Vauxhall Astra that went into limp mode when I was going about 65mph. I pulled it off the road and the car would not start, it would crank but not ignite. After being recovered home I had a local mechanic out to take a look, he discovered that one of my spark plugs has been smashed, most likely after being hit by piston. The timing chain had slipped a little too. I was told that it would most likely need a rebuild and was quoted £1500 for the job. Would I not be able to just replace the spark plugs and coil pack and save myself all that money?
If your timing belt has slipped then it is likely that the pistons have hit the valves and it is a damaged valve that has smashed the spark plug. The damage inside the engine is likely to be expensive.
Answered by Honest John on

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