Chrysler Neon Immobiliser

Hi can anyone help? I have an S reg Chrysler Neon LX, and have a problem as the immobiliser lock/unlock units (fitted to the key ring) have become very unreliable, my Chrysler dealer tells me that the units cannot be individually replaced but I need to buy 2 new transmitter units (ie the key fob bits) and a new receiver that fits in the car itself. This will cost over =A3300 and I could fit a far better alarm/immobiliser for that sort of money!! Has anyone else had this problem and have they managed to overcome it, can it be done by isolating and removing the immobiliser?? =20 Many thanks Jerry