Yeah, that number is just impossible if it refers to the average or expected curation rewards + benefactor rewards projects gets.
At SteemPress, we do around 8k per month, which also includes benefactor rewards. As outgoing steempress votes only make up about 25% of it (meaning most benefactor value stems from other community votes on steempress content), it would be closer to 5,000 SP per month as a base line (prior to HF21 at least).