Buy or develop your own time machine and go back to 2008 and mine BTC on the computer at your mothers house in the basement
I think you can not overnight to become rich, should be done to establish some of their business to become rich . They should also have some luck in life, but needs a lot of work and effort. You should be at the right time in the right place .
Few years ago.
My friend told me that he's going to buy 10 BTC for around $20, I wasn't actually interested in it and I didn't buy anything.
When I see the price now I want to kill yourself I didn't buy any, really. I'm dumb.
As someone else pointed out earlier, buy some BTC now. You are taking the same risk as your friend did back then. Either it will go up or down, but if you believe in it you will kick yourself harder in a one, two, or even five years down the road.
I am sure when BTC first hit $2 there were people saying the same thing; why didn't I buy when it was $0.02 or $0.20, etc. Then when it first hit $20, why didn't I buy at $2?. At $100, why didn't I buy at $20, etc.
So my point is if BTC ever gets mainstream its value will skyrocket. Think about it, only 21 million coins divided up amongst 8 billion people on the planet. That is roughly a 380 people per 1 BTC ratio, so BTC will be very scarce by then. Heck even if one country, say the US at 350 million people to only 21 million BTC, you get the picture.
So if BTC would get to be worth $10,000, $100,000 or even $1,000,000 per BTC, buying at $100 versus $300 becomes almost a moot point. And before thinking such a valuation couldn't happen, consider the GDP of the US in 2013 was approximately 16.77 trillion dollars. I know that is is far from evenly distributed (99% versus the 1%, etc) but for simple math, look at dividing that $16,777,000,000,000 by 21,000,000 coins and they would need to be worth $798,904 each just to sustain one countries economy. BTC is a global currency, so it could be higher. Of course this is the extreme in price prediction and is not very probable, but it does illustrate the potential should BTC get a mainstream foothold.
We already seen one peak at over $1,000 per BTC, and I as many others believe the current price suppression is mainly due to big players buying up the cheap coins (the 0.01%ers). Now is the chance to join them.
there is a logical fallacy here, because the more we go high the more hard is to go even higher, so buying at 1/5(like in your example of hit $100 i buy at 20 ecc..) of the maximum isn't always good if we have already reached a high amount, the chances it will fall are much higher
besides this there is no guarateed that bitcoin will skyrocket that's the problem and this is the reason why i said the above thing
And your chances are greater. 
