Immobiliser problem / replacement

[lazyitus]

My Griff has now twice immobilised itself when on the move. Luckily I've been able to stop in safety but this is a real concern.

I know its the immobiliser as I have to re-arm and then disarm it again before it will start.

Anyone know the cheapest option to replace the system as I'm already down to one fob aswell after the other packed up.

?

[WildfireS3]

If it's a CAT1 then the base price is about £300 for Cobra, Autowatch and Clifford.