the main mount that breaks is the dog mount
on the right side of the engine from the drivers seat
the left if you are facing the car
it usually breaks down easily usually this one needs replacing as i am on my 3rd
the main one in front by the base of the rad is a hydralic one that should last much longer but not if the dog mount as failed for a long time
causing too much undue stress on the lower hydralic one
dog mount it 2 bolts 10 minutes to change
part is 40 dollars
the lower one is much more that must be where your high bill is coming from