I have some 问题 about comic con...

ok. i need to know some stuff about Comic Con. so first, i know the tickets are expensive, so when i get in, is every thing else (the signings, interveiws with actors, that kinda stuff) free? Two, what is the latest i can buy a ticket(im saving up myself, and need $200. thats not gonna come easy...)? and third, what kinda stuff is inside?
if 你 answer, then thank you!