This is a nice idea, but even if you throw away posts with vote selling services' and bots' rewards, I think that we still can't say that there is a strong correlation between high payout and a quality content.

My suggestion is that you could follow also trusted community members and try to get data about where their upvotes are going. For example you could follow Curie curators, their job is actually to find a good, exceptional content and based on their and Curie upvotes you could improve your model.

One question - how do you curate art content like photos, paintings and travel posts with a lot of photos?