Every time there is luck, any capital will definitely be big, at least we can go through the right stage, which means the same as your friend's story with $500 within a week.
So with minimal capital it can be played again but full of awareness.
You can make fortunes in gambling if you are lucky or even if you have deposited small capitals it will not matter and you can have big profits like $500 within a week also but if not then you might lose all the deposited funds also.But yes duelbits provide opportunity to small gamblers with many bonuses and promo codes with giveaway which are sort of additional benefits to players not too much but still it's good for them.