There's no need to risk anything if you are worried the price might go down. If you are prepared to buy bitcoins to then use them to buy goods, you can basically take one of two options depending on how risk-averse you are.
Option 1: To do this, you just need a small float of bitcoins. Don't buy the coins first, but rather hold the money (temporarily) as cash at the exchange until you are ready to purchase something. Then, once you make the purchase (with your float), you can immediately re-buy the coins at the current price. The net effect is the same (fiat -> BTC -> goods), but you have risked nothing.
But it's more complicated than fiat -> goods because I have to then transfer fiat back into the exchange.
Option 2: If you are confident prices may rise or at least stay the same (and can handle it if you are wrong), buy the coins first and then buy what you want with them. You may wind up getting a deal in the end vs if you had bought with fiat in the first place. There is risk this way, but as I say - if you can't handle that, go with Option 1.
Right, and that's my strategy (I'll leave the speculating and day trading to others), but with that strategy, I'm not going to buy coins first if I feel there is market manipulation driving the price up to $200 when it doesn't belong there, because then I'm buying high, not low.
I'm not in the country club that knows when the manipulation will end and get out before the correction. I leave that to the day traders. Not my thing.