High power bill? It depends on how powerful you make your coil. My mini coil uses a 7500V 30mA neon sign transformer as the power supply. This is only 225 Watts of power. Plus, most people only run a coil for a few minutes at a time. Your power usage is likely to be minimal.
Here are some links to help get you started:
http://www.teslacoildesign.com/
http://deepfriedneon.com/tesla_frame6.ht...
It's a very basic device and it requires very little material which you can get a hobby shop. Most items you will get won't produce much. You can even get the raw materials yourself and tune them to work to a larger scale. Only problem would be that you won't have enough electricity if you did. Another problem you might encounter, is that Tesla coils run on small current while electrical sources run on high current. The issue becomes that you may destroy your coil. If you truly want to build one without damaging yourself, you might want to design a circuit to reduce the current and increase the resistance. Tesla coils output large sums of power which can be explosive/deadly. Resistance is your enemy. Ideally you want the system to increase resistance when things get bad. This can be by passing a large resistor in parallel to your other circuit. If your system begins sending out too much electricity, the large resister will regulate it. It might even be better if you install a large set of capacitors to shut down the system automatically after they charge.
Yes and not if you power it with a Vann Der Graf generator.
No
I am 17 year old and I am really into electronic stuff and everything, and I was always interested in building one..So I got 2 questions.
Is it possible?
If it is possible, will my father kill me at the end of the month if he sees the electricity bill??
(Sorry, I am not the best at explaining this stuff on english, cause I know 5 languages and I'm not from USA or England or any country that speaks english, I come from Hungary and it's a completely different language, sorry again)