I have spent $25,000+ on my 260z and I'm nowhere near done. It doesn seem like much but like the other have said... take the price you figure and times it by four... I only planned on spending 10k MAX.
You either go the cheap route and keep it stock and drive it the way it is, or have the passion and money to make it into a street machine...
If your not either of those I would look for another car, because as deceptive as it may seem, making a hybrid z costs TONS and TONS of money and TONS and TONS of time.
Heres my car If you wanna see whats done to mine
www.cardomain.com/ride/3218401
Yup, $25k+....