On top of the actual registration you have stamp duty, I cant remember how much it is, something like 10%?
If the car is not already registered on the mainland, you can get a non registered permit from service tas for like $40. This allows you to drive your car from where it is, to where ever in Tas, to get inspected and then registered.
Without this unregistered permit, you are unable to get your car insured until it is registered.
Ive heard of some guy who had bought an R34, didn't do this, was going to get insurance the next day and had an accident, car was a write off...
Insurance, I'm with Just Car, and pay nearly $900. I'm under 25, so it could be less for you.
Just Car have a really good insurance quoting system on their website, so check it out.