Someone ask me a question after introducing bitcoin to him, if he can start up with $30 and grow with it but I told him bitcoin is wide and high in volume, price and market, that's means whatever you're starting with determine the outcome of the market like for example; if you start with $30 and eventually the market goes up to a little increase of $32 can not be compared with someone who started same time with you, at the rate $100.
So also when the market is down to some extent, the person with $30 may likely loss more because of the money is small. Blockchain has the minimum amount one can invest if am not mistaken but if your amount is too small may be difficult to make easy progress.
What do you think about my advised to him?
I think that investing any amount in bitcoin should be based on several things, first and foremost is that you should never be investing money that you can't afford to lose, meaning don't go about taking loans and credits just to invest, because it is a risky business and you might lose it, second of all what is you goal and what are you trying to get out of investing, are looking for long term investment or short term, and if you are just looking to actively trade it or just invest and leave it, in my experience if you are going to invest a small amount like 30$ you would have to be actively trading it , because lets say you bought it now and bitcoin goes up to 100k , you would only have made 70$, but lets say if you invested 30$ and sold and bought based on market prices you could grow that amount.