Wire, connectors, shrink wrap, nuts and bolts, zip ties, battery strap, etc... ya know all the little stuff that adds up and eats 25% of your budget. Then you need the usual stuff, A body, wooden dowels, control board, 3 motors, 3 ESC's, ESC programming card (optional, but recommended) Props, prop adapters, a better then average servo with metal gears, mine was $20. You also have to decide what kind of tilt control you want. The cheapest one to make is David W.'s (RCExplorer.se). Like mentioned above if you have some of the stuff laying around already you may squeak in for $100, but $150+ would be more realistic.