For what it's worth, I sometimes vote on a $3k-type post so I can actually see my vote make a difference for the author. It's cool that even as a small fish I can participate and help them get a couple bucks. 

At first I was really trying to maximize the value of my upvotes. I was all focused on getting in early on the posts destined for the top. At my levels of steem power though, all of my curation rewards are way less than ten cents. So for now, I get enough satisfaction from seeing an author's post get a boost that I go for it sometimes.