I'm not sure if you already bought, but if you want in the market, this is how you do it:
1) Buy some bitcoin now at a price of 450 (for example 0.5 BTC)
2) If price goes down to 400, then buy another 0.5 BTC (or 1BTC)
3) If price goes to 350, then buy 2 BTC
4) If price goes to 300, buy more
5) If price goes to 100, buy 10 BTC.

Pretty simple really.