I know huge capital is required to meet up huge financial expectations, what's the minimum volume of income one can use to start mining? In a situations where you trade with different strategies and still hits wrong targets, if you apply or use same trading knowledge for mining won't one still loss in mining too? Because I don't have enough money with me, so am trying to cut losses if mining too will not favor me I will decided to venture into mining too again.
Can I start mining with $300 and grow from there?
You can literally start mining with the computer that you are using to post this topic on the forum. You just would not earn a lot since the computing power is considered nothing special (unless you have a really awesome and expensive hardware setup).
I think the question you want to ask is how much money do I need to invest into mining Bitcoin for it to become profitable by an x amount of percent, in regards to the money that I put in? That might be a bit more difficult to solve since you have to consider the costs of miners, electricity, internet, space and so on...
So the most necessary question to figure out your costs is: how much money, at minimum, do you want to make?
You can earn a few dollars a month mining on a computer if you are 14 years old and your parents bought you a computer and pay utilities. In Russia, such people are called "mom's miner". Your computer will probably need to be repaired. If you pay for utilities yourself, then in a few days you will realize that this is an unprofitable activity.