I am not an expert but I do like to share my opinion. 

well from what you have provided and my level of maths, your goal is to make around $150 of steem a day. and that of your $200 goal, $50 would go back into the steem power.

and so the next problem, how would I make around $150 dollars a day? of steem, that is? 

well, you would have to make some really awesome content, at least once every 3 days, which would allow for the payout of around, 12-14 steem dollars. so if the exchange rate is increasing then the SBD would be able to buy more steem, so less would be needed in order to make that roughly 12-14 dollar a day goal.
I say this goal as the payout per post takes a week for you to claim your reward. 
so ill let you decide how much you should post a day.

 as it is an inverse ratio of the quality/quantity sort of thing, if you can find a good equilibrium, you can make quality content in a quantity that would allow you to reach your yearly goal. 

Although I am no financial adviser, there is one common rule of "money making/investing" is to diversify in order to not rely on one thing and to mitigate risk such as the stability of the currency. 

or something like that. 
I hope that this helps!
thank you for your time and I hope you have a good one!