What will it cost to repair engine mount? on 2006 Buick Lucerne

I understand that the Buick Lucerne 2006 is plagued with poor quality engine mounts. My front engine mount is broken and needs to be fixed. What is a reasonable price for this and do I need to have all the engine mounts fixed at the same time??

1 answer 2 comments
need more info on mount location. upper or lower and approx location. repl as they break unless the others are worn or cracked at rubber
it is the front one lower
repl as required and ck the other mounts