the main strategy is to buy bitcoins and sell it for bigger price in the future
Lol don't invest so much in to bitcoins.
It should be apparent that it's too volatile and risky for such large investments.
Diversify your portfolio as they always say
Agreed with you, one can not just depend on bitcoins to became rich. Its totally like a day dream, you can invest some part of your saving into the bitcoins as investment and if the price of bitcoins start decreasing you will not have huge loss, it will minimize the risk. There are many options available for investments wherein you can get good returns. But I think hard work and luck is very important to get rich.