Insurance Quotes: Explain how this works

[AWD Chaser]

Hi guys.

My brain has now melted after talking to NRMA and getting some quotes for insurance for the cars:

Heres the following:

2002 Ford Falcon Futura (ins for $12000) - Garaging Address - NSW (Address not revealled), 4 years driving experience, no claims, thefts, etc... No fines in the last 3 years

Quote = $83p/m

AND

2006 Kia Grand Carnival (ins for $30000) - Garaging Address (as above), 4 years driving experience, no claims, thefts, etc... No fines in the last 3 years

Quote = $85p/m

Now here's the weird part. If I choose to insure the falcon for any more the $12000, the quote starts to go up.... yet the Kia ins. for $30k would be less then the falcon.... but the Kia has more power - it has a 184kw motor as opposed to the Falcons 157kw motor (I think the dyno must be broken because my falcon has at least 800rwkw - I just know it - lol). So WTF?

The other weird one - If I choose to insure my Falcon at either the NSW address or my other ACT address, the price does not change... however, if I choose to insure the Kia at the ACT address instead of the NSW one, it will cost me an extra $200 per year? I can understand the difference if it was for both cars, but only for one? WTF?

So does NRMA have any standard in pricing or just pull figues out of nowhere?