I would suggest you to buy something like 5 bitcoins when the Bitcoin price is 280 USD, and sell 4 of the coins when the price is around 350 USD,
5 X 280 = 1400
4 X 350 = 1400
so you will get 1 btc free of cost.
the big question now is when will the price of bitcoin go down to 280? you can't just say things that unlikely to happen right now
Yeah going down to 280 dollars again is if you are lucky to buy bitcoin with that amount that it goes low.
Me personaly I think that bitcoin will just be around 300 dollars.
So better buy now some bitcoins. Just little amounts that you will make later 1 bitcoin and who know maybe 1 BTC will be around 650 dollars.
IMO $300 is the bottom level. When it approaches that level again, then you could buy 1 BTC or 2 BTC based on how much you can afford to lose, although it have a lot of potential we believe it deeply.