Ignition Barrel Problem

[cnr]

Have a problem here with our friend's 99 Corolla saloon, specifically with the ignition barrel. If I put in the ignition key on its own, it refuses to turn. If I put in the boot key first and then take it out, I can then put in the ignition key and turn it no problem.

Local Toyota dealer first suggested that it could be repaired by replacing the barrel, at a cost of €100-ish. However, now they're telling her that "you have to buy the whole kit", which is at a cost of €380+fitting of €70 or €80.

What I need to find out is whether they're spinning us a story about needing a full kit and also whether there is an alternative source for these barrels.

Finally, I understand from another thread on these forums that replacement of the barrel is easy enough but will I need any connection with the immobiliser to effect the change?