I think it is unlikely you will make a profit unless your blogs are really good and you get lucky. Hopefully what you will get are some followers who will follow you for years. The value of that is hard to calculate.
My advice is to mainly look for steemians who already have earned a few hundred steem. This means they are getting bigger in steemit. Hook them now while they are still small and they will appreciate your conversation on their blogs. Try and get in early, preferably within half a day of the blog being published. That way other commenters will see what you have written.
Before you start, make sure your latest blog is the most brilliant one you have ever written. People reward hard effort more than lazy effort.