Same idea. This came up before territories launched and we were trying to think through how to reduce the spammyness of the main feed.

My simple idea was to have posting fees = the number of posts in the past hour. Back then the posting fee was only one sat.

To update the idea, we'd probably want each territory owner to be able to set their own peak-pricing mechanism. Now it would help address the issue of low territory revenue, in addition to cutting down on spam.