I like this proposal.

Edit: I do see this:
> post duplicates
When you post a story that has a highly related title to something else that's been posted, you'll see a 'similar' section underneath your post.
>
> This is a soft nudge to not repost a similar story. We might do harder nudges depending on how this goes.

[source](https://stacker.news/items/121947)

I was not aware of this. Perhaps the nudge is too soft ;)

WeAreAllSatoshi

SN Feature Proposal: Enforce Link Post Uniqueness (timeboxed)

I think the balanced approach is
- Let users submit another of the same link, but it should cost more, especially if the link was posted more recently (I thought this was implemented already?)
- In both posts also show reference to the other post, e.g. expand the "related" section with "Link was also posted under XXX")

So this both creates more sats income to SN for undesirable behavior (reposting same link) and it let's posters compete for who posts the best and it lets the readers to have full context and see all available threads. 