I'd agree completely with this.. I brought mine (32 GT-R) 2 weeks ago and within a week, i've had to spend on the following.
Rego Transfer Fee - $30.50 plus $8 for every $200 value of the car, so a $16000 car would cost you $670.30 (calculator).
Airocn Re-Gas $120
Alarm + Install $390 (make sure you become an SAU member, good discount on alarm install).
Blown Radiator hose $80 (top and bottom silicone hoses)
Wheel balance $??? not got this done yet, but it threw a balance weight within the first week, vibration above 100k's.
So that's already $1260 or more on top of the purchase price. As with any new car i'm going to get it serviced quite soon, you have no idea of really knowing when the last one was done, even if the previous owner says it's just had a service. From what I understand, a service can cost around $1K depending on what needs doing (hope mine doesn't need cam belt etc).