It's real simple. If you put a buy order at 1000, and wait for price to come down to you, then there is zero slippage. If you get in early, you will get filled, and the bid will still be 1000 and the ask will be 1000.25. You could literally turn around and immediately sell for what you just paid for it.
Also, if you just buy market just before price flips up, then there is no slippage.
You should spend some time watching the markets pre market, when action is very slow, to get an idea of how to deal with slippage.
Also, you would probably do better with 3 contracts and shoot for 33 points, as opposed to doing 33 contracts and shooting for 3 points, especially if you don't already know the answer to the questions your asking.