Spoofing callerid... How much to do this?

I used to use calleridfaker.com which gives you 2 min before it cuts you off to call someone and spoof your caller id. I paid for unlimited calls through calleridfaker.com but after 400 minutes they terminate your account saying you must be using for business for that type of usage! Ridiculos, Unlimited should be unlimited. Any other ideas???

Someone told me about just getting an Asterisk server. I DO NOT want to spend alot of money, and an a total newbie here. Thoughts?