If they sell you the ignition switch they will mark up the cost most likely, that way they cover labor if they ever have to work on it again, at least that is how they do it here in the states.
You are right, I'd expect to pay at least around 500.00, more if they have to replace the ignition cylinder, and the BCM, then program it.
Here in the states I have heard of some paying from 500.00 to 750.00 for the total job, prices vary though.

Have you had it tested yet to see if it is the ignition cylinder, or the BCM?

not yet, need to take it to test it, probably at the dealer too, and hope they have the tools to do it haha

Oh they will have the tools, as long as you have the money.
You'd think they'd test to see what is wrong for free, because all they do is hook a scanner to it, but I am pretty sure they'll want some money for diagnosing the condition.

i have scanxl pro, can i do it myself? o:

No, only GM Tech2'* diagnostic tools can test everything on a car.

This bothers me to no end. Everyone wants something for free. Well I have to eat too. Further more the tech2 doesn't tell me what'* wrong. It gives me info to allow my diagnosis to be correct. You wouldn't expect a doctor or a appliance repair man to diag. something for free would you? At my shop you pay for diag. once. If it still isn't fixed right, I eat it next time. Flat rate sometimes can be a b*tch, and the general public doesn't understand how it works for us techs that work in a shop.

No need to get upset, I have been a business owner for a few years in the past, and I understand how easy it is to get aggravated when people want something for free, but if you think about it what do you do after you use the Tech II on it?
Let'* say it points to the BCM, do you do more testing with some other tool, or do you just charge them to replace the BCM?
If it points to the ignition, do you replace that ignition switch, or do you do more testing?

Once you find the problem you can make good money by the usual marking up the part, and the labor fees.

I can see if the diagnosing takes a long time, then of course you deserve money for your time spent, but to be honest I am not sure the proper procedure involved in the diagnosis of this problem, just what exactly do you do to diagnose this problem, before putting the Tech II on it I mean?

i see, well to the dealer will it be.

to be honest im afraird to drive the car haha, i dont trust it anymore, i will tow it to a dealer even knowing that it moves.

:( thats how i feel.

If it is the security system like the codes say, then I'd not worry driving it there as long as you do not shut it off till you get it there, the security system is designed so that if it has something fail that controls it, then the vehicle will keep running till you turn it off, it is a limp home mode basically.
If you want to tow it I'd at least drive it as far as it will go, which should be all the way there as long as it starts, if it shuts off then you know that there is something else wrong as well, and then you can just go ahead and tow it.
If you make it you save money that you will need to pay the dealership.

When it comes to diagnostics with the Tech2, I wouldn't mind paying the $80-$100 for it. Does anyone know how much those Tech2'* cost? $4000-$5000 a piece. It is the only device in the auto world that can "talk" to ALL of the modules in these newer cars.