I love this idea because some people create posts that are complete crap just to vote themselves more rewards.

Maybe we should not limit the persons number of posts, but limit how many posts they are allowed to get any rewards for... like after the first post, the rewards would be reduced by 75% and the post after that the reward would be reduced by 90% until if they posted say more than 4 times in a day, only the first or maybe second post would be worth posting simply for the monetary value.